Dr. Santosh Kumar, Professor, Liaocheng University, China (SPIE Fellow Member, OPTICA Senior Member, IEEE Senior Member)
Santosh Kumar is a highly accomplished researcher and Professor with a Ph.D. degree from the Indian Institute of Technology (Indian School of Mines) Dhanbad, India. Currently based at Liaocheng University, China, he specializes in optical fiber sensors, nano and biophotonics, photonic and plasmonic devices, as well as waveguides and interferometers.
Throughout his career, Dr. Kumar has successfully supervised twelve M.Tech. dissertations and mentored six Ph.D. candidates. He boasts a prolific publication record with over 310 research articles in prestigious national and international SCI journals and conferences. Driven by his commitment to advancing knowledge, he has presented his work at conferences held in China, India, Belgium, and the USA.
Dr. Kumar is the author of two scholarly books, "2D Materials for Surface Plasmon Resonance-Based Sensors" (CRC Press, 2021) and "Optical Fiber-Based Plasmonic Biosensors: Trends, Techniques, and Applications" (CRC Press, 2022). His expertise is highly sought-after, reflected in his extensive reviewing contributions for over 1750 SCI journals published by renowned publishers such as IEEE, Elsevier, Springer, OPTICA, SPIE, Wiley, ACS, and Nature.
Recognized for his achievements, Dr. Kumar is a Fellow of SPIE and a Senior Member of IEEE, SPIE, and OPTICA. He serves as an OPTICA Traveling Lecturer and holds the esteemed position of Chair of the Optica Optical Biosensors Technical Group. He has delivered numerous invited speeches and serves as a session chair for IEEE conferences.
Additionally, Dr. Kumar has made significant editorial contributions, serving as an Associate Editor for journals such as IEEE Sensors Journal, IEEE Internet of Things, and Biomedical Optics Express.
Publications (77)
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This research aims to identify the presence of early-stage cancer in individual living cells through the utilization of a surface plasmon resonance (SPR) prism-based biosensor device. The proposed investigation employs SPR phenomena to differentiate between healthy and cancerous cells, employing a multilayer sensing structure. A BK7 glass prism is used as the sensing platform, coated with a nanocomposite layer consisting of gold (Au), titanium dioxide (TiO2), and graphene. The refractive index (RI) range of cancerous adrenal gland (PC12) cells is found to be between 1.381 and 1.395. The numerical results demonstrate that the proposed biosensor, equipped with single and multilayer nanocomposite structures, exhibits high sensitivity, figure of merit (FoM), detection accuracy (DA), and signal-to-noise ratio (SNR) for both healthy and cancerous PC12 cells. As the concentration of cancerous PC12 biomolecules increases in healthy cells, the SPR angle shifts, indicating variations in the refractive index due to the presence of cancerous cell biomolecules. The measurement of refractive index modifications in cancerous PC12 cells of the adrenal gland is achieved through an angle interrogation approach. Various thicknesses of TiO2, Au, and graphene layers have been improved to enhance the performance of the biosensor.
Vitamin C, or ascorbic acid, is a vital nutrient with significant implications for human health. Accurate and rapid detection of vitamin C concentrations in various samples holds immense importance in medical, pharmaceutical, and food industries. In this study, we introduce a novel approach utilizing an etched fiber-based plasmon sensor for sensitive and selective detection of vitamin C. The biosensor employs a gold-coated optical fiber with a precisely etched region, enabling the excitation of surface plasmon polaritons (SPPs). The interaction between SPPs and the vitamin C analyte induces changes in the refractive index near the fiber surface, consequently causing shifts in the resonance wavelength of the plasmonic mode. By monitoring these wavelength shifts, the concentration of vitamin C in the sample can be accurately determined. This research presents a promising platform for enhanced detection of vitamin C, offering potential applications in various fields.
The increasing concerns regarding the health risks and economic impact of food adulteration, particularly in honey, have sparked significant attention. Ensuring the quality and authenticity of honey relies on the ability to effectively detect adulterants such as glucose. This research focuses on the utilization of etched fiber Bragg Grating (eFBG)-based sensors for monitoring honey quality and detecting cases of glucose adulteration. FBG sensors offer numerous advantages in detecting food adulteration, including their exceptional sensitivity, real-time monitoring capability, and non-invasive nature. This paper provides a comprehensive account of the experimental design and data collection procedures employed to develop FBG sensors optimized for glucose detection in honey. Furthermore, coating the eFBG sensor with reduced graphene oxide (rGO) has shown better sensitivity due to its unique properties. The achieved sensitivity found is 43.56 nm/RIU with rGO-coated eFBG sensors. The results demonstrate the ability of FBG sensors to identify honey adulterated with glucose, highlighting their potential in enhancing food safety and quality control measures.
Edible oil adulteration poses a significant threat to public health and erodes consumer trust in the food industry. This study presents an innovative approach to detect edible oil adulteration by leveraging the capabilities of Fiber Bragg Grating (FBG) sensors, known for their speed and accuracy. The FBG based sensors were employed to monitor the refractive index (RI) of edible oils (pure coconut oil), enabling the identification of adulterants introduced during the adulteration process with a lower-quality oils such as paraffin oil. Rigorous experiments were conducted to assess the reduced graphene oxide (rGO) coated FBG sensor’s efficacy in detecting adulteration. The remarkable sensitivity and specificity of the rGO-coated eFBG sensor were demonstrated through its ability to detect and measure even minute changes in RI induced by the presence of adulterants. Utilizing rGO-coated eFBG sensors yielded a sensitivity of 26.62 nm/RIU. Indicating the potential of FBG sensors to improve food safety and quality control regulations, the results exhibit the capability of these sensors to detect paraffin-adulterated coconut oil.
Dopamine, a vital neurotransmitter in the human body, plays a crucial role in various physiological functions and is closely associated with neurological disorders such as Parkinson's disease. Timely and accurate detection of dopamine levels is essential for effective disease management and personalized healthcare. In this study, we propose an innovative optical fiber-based biosensor utilizing the Localized Surface Plasmon Resonance (LSPR) effect for highly sensitive and selective dopamine detection. The biosensor probe is fabricated using a SMS (Single mode fiber-Multimode fiber-Single mode fiber) optical fiber structure, which is chemically modified to enhance the LSPR effect. Gold nanoparticles are employed to amplify the plasmonic response, enabling improved sensing performance. Experimental analysis is performed using dopamine samples, and the results are obtained using a spectrometer. The developed LSPR biosensor demonstrates great potential for precise and efficient dopamine detection, paving the way for advanced personalized healthcare and improved management of neurological disorders.
KEYWORDS: Modulators, Modulation, Signal generators, Microwave radiation, Signal detection, Radio optics, Modulation frequency, Signal attenuation, Data transmission, Microwave photonics
This work demonstrates the implementation of a microwave photonic technique for generating a frequency-quadrupled microwave signal. The approach involves utilizing a parallel Dual-Drive Mach-Zehnder Modulator (DDMZM) driven by an electrical signal, while applying appropriate dc biasing to the DDMZM electrodes to suppress or eliminate the odd harmonic components of the sidebands in the optical domain. The DDMZM is operated at its maximum transmission point (MATP). To eliminate the optical carrier, an optical notch filter with the same central wavelength as the carrier is employed at the output of the DDMZM. This setup yields two optical sidebands. By detecting the beat signal at a photodetector (PD), a fourfold increase in frequency relative to the input RF signal is achieved. The input microwave signal frequencies of 15 GHz are utilized, resulting in output microwave signal frequencies of 60 GHz, 120 GHz, respectively. The generated frequency-quadrupled microwave signal can find applications in areas such as high-speed communication systems, radar systems, wireless networks, and satellite communications, where higher frequency signals are desired.
This paper presents a novel approach for pathogenic bacteria detection (PathoBactD) through the utilization of a surface plasmon resonance (SPR)-based biosensor. The sensor consists of a BK7 prism coated with silver (Ag), barium titanate (BaTiO3), and molybdenum diselenide (MoSe2) in the Kretschmann arrangement. The proposed SPR-based biological sensor incorporates the concept of attenuated total reflection (ATR) for accurate measurements. Various performance characteristics of the sensor, including sensitivity, figure of merit (FoM), signal-to-noise ratio (SNR), detection accuracy, and quality factor, have been thoroughly analyzed. The integration of BaTiO3 significantly enhances the sensor's capability for PathoBactD. To evaluate the impact of the BaTiO3 layer on the performance parameters of the MoSe2-based SPR biological sensor, a theoretical model employing the angular interrogation technique has been developed.
High speed photonic links require optical filter with high quality factor and free spectral range in GHz range. Such requirements motivate us to explore the characteristics of new configurations with various types of optical components and tuning mechanisms. In this work, different structures of dispersive elements are investigated to monitor the filtering scope of a microwave photonic link. The spectral characteristic of the optical filter is demonstrated in terms of normalized intensity and free spectral range. This study focusses on the various configurations with multiple number of optical components under test to reduce the ripple in the pass band of optical filter and to get linear phase response for distortion less transmission. The possible power tuning mechanism of the proposed structure is explained through various coupling coefficient and Mach-Zehnder interferometer structure. This helps in the design of tunable optical filters. Furthermore, the investigated elements are implemented in the design of optoelectronic oscillator for the generation of arbitrary shaped microwave signal. The chirping capability in the generated signal is introduced for energy efficient transmission of the signal in modern radar systems. The overall model is theoretically analyzed, and results are demonstrated through MATLAB simulations. The performance analysis of proposed optical components is demonstrated through microwave photonic link in Opti-System.
This paper provides a comprehensive characterization of a graphene based microstrip antenna which shows plasmonic behaviour at terahertz (THz) frequency spectrum. The study focuses on analysing the behaviour of Surface Plasmon Polariton (SPP) waves in graphene sheets through the design and analysis of a rectangular patch antenna. The unique properties of graphene are analysed, and a thorough numerical and analytical investigation of SPP wave propagation in graphene is conducted. The dispersion equation, as well as the intraband and interband conductivity of graphene, are explained using Kubo's formula. The patch antenna is designed to operate at a resonant frequency of 0.55 THz, and its electrical characterization is performed using the High Frequency Structure Simulator.
Terahertz antennas have garnered significant attention, particularly in the fields of photonics and wireless communication. Graphene, renowned for its exceptional strength and thinness, exhibits remarkable properties when employed as an antenna element for radiation. Its conductivity varies with thickness and can be controlled through biasing voltage. To mitigate surface wave effects, photonic band gap crystals serve as suitable substrates. This study proposes an antenna structure comprising a miniaturized patch fabricated from graphene material on a photonic band gap (PBG) substrate of Arlon, operating in the terahertz frequency range. A comparative analysis of the antenna structure with and without PBG is conducted, and the obtained results are discussed. The proposed antenna demonstrates optimal performance in terms of return loss, gain, and voltage standing wave ratio (VSWR) across multiple frequency bands within the terahertz spectrum. At 1 THz and 1.18 THz, it achieves an effective gain of 4.53 dB and a return loss of 22 dB. Additionally, various electrical properties, such as surface current, current density, and VSWR, are analysed. The simulations are conducted using the High-Frequency Structure Simulator (HFSS). With a compact volume of 500 μm x 500 μm x 200 μm, the proposed antenna structure is suitable for various optical applications, including nano-sensor networks and imaging. Encouraging results are demonstrated at higher optical ranges within the terahertz band.
Microwave waves play a crucial role in various fields, including data transmission, sensing applications, and seismology. The advancement of technology has led to the increased use of microwave waves due to their wider bandwidth and higher frequency capabilities. However, conventional electrical systems often produce microwave waveforms with limited bandwidth and predefined frequency ranges, which may not be suitable for all applications. In this study, we focus on producing an arbitrary dual linear chirped microwave signal that offers configurable bandwidth within a predetermined frequency range. Our approach relies on optical external modulation as the foundation of the photonic method. By cascading two Mach-Zehnder Modulators (MZMs) functioning at the Minimum Transmission Point (MITP), we effectively suppress carrier signals in the modulated output. Through this technique, we successfully generate dual linear chirp microwave signals by superimposing an electrical baseband chirp signal onto the externally modulated signal in the optical domain. This approach demonstrates the potential to create microwave waveforms with wide bandwidth and linear chirping, opening up new possibilities in satellite communication, radar systems, and other advanced applications.
KEYWORDS: Antennas, Signal generators, Modulation, Microwave radiation, Reflection, Near field optics, Ku band, Design, Phased array optics, Optical amplifiers
In this paper characteristic of the microstrip patch antenna for X-band and Ku-band has been validated while deploying photonic –assisted excitation to demonstrate efficient transmission and distribution of the RF modulated optical carrier. To demonstrate the microstrip patch antenna behaviors under photonic-assisted excitation a four element antenna array excited by corporate feed network is design and fabricated for efficient optical beam steering application. In this paper antenna performance characteristics are analyzed in the presence of RF and photonic excitation. It has been found that the performance of the antenna through photonic-assisted feeding is much superior to the RF feeding of the antenna. The proposed antenna has > 100 MHz of bandwidth corresponding to 9.0, 13.0, and 18.0 GHz resonant frequency respectively. The max peak gain of the proposed antenna is 14.6 dBi.
The current research proposes the development of a plasmonic elliptical ring resonator structure with a Metal (Ag) Insulator Metal (Ag) waveguide configuration for the purpose of bio sensing. The research involves a distinctive exploration of the sensitivity and peak resonance wavelength, which are found to be varied by altering the aspect ratio of the elliptical ring resonator. The results reveal a marked increase in sensitivity, ranging from 732.60 nm/RIU to 1113.70nm/RIU, by changing the aspect ratio (ratio of major to minor radius of elliptical ring resonator) from 1.61 to 3.72. Furthermore, these adjustments produce a noticeable redshift in the peak resonance wavelength, as the aspect ratio increases. The study also highlights the impact of other geometrical factors of the sensor on its sensing characteristics. It is found that sensitivity changes significantly with the change in width of resonator and linear waveguide, and it is found to be decreased when width increases. The results of variation in width of waveguides reveals that there occurs a red shift in resonance wavelength when width decrease and vice versa. Based on the finding of all significant geometrical factors an optimized structure is selected with the optimum value of sensitivity. Which evidences its suitability for biosensing purpose and with its superior capabilities, the sensor can play a crucial role in distinguishing between healthy and cancerous cell and will be helpful in detecting cancer at early stage. The investigation and observations involved in the process are computed numerically using the finite difference in time domain method (FDTD).
The current work proposes an optimized design for 2-bit synchronous up counter using silicon nitride on insulator optical microring resonators (MRRs). The research involves exploring the existing designs of up counter structures based on MRRs, and then minimizing the number of rings being used in the proposed model. The proposed design uses four MRRs for Synchronous up counter operation and the model has been validated through the MATLAB simulation result. The main component of the design is the MRR which can act as a switch depending upon the output at the drop port or the through port according to the MRR being in an on-resonance or off-resonance state respectively. The principle of the MRR is that on applying a vertical pump signal over the ring, the non-linear refractive index of the ring undergoes a temporary blue shift resulting due to π- phase shift in the ring, changing the resonant frequency of operation of the ring. The average pump power required for the blue shift can be obtained from the phase shift vs. the average pump power graph simulated in MATLAB. This shift in resonance frequency is employed to switching action for the signal to be output at the drop port or the through port of the MRR and based on the drive signal inputs of the present state and the clock to the rings in the resonator structure which act as pump signal over the ring, the next state of the counter is determined.
Tyramine plays a very important role in the proper gastrointestinal function of the human body. By detecting tyramine concentrations, it can be inferred whether the human body is performing normal activities. In this paper, a fiber optic biosensor based on a cladding-offset structure (COF) is proposed to measure tyramine solution at various concentrations. The evanescent field around the probe sensing region is enhanced by etching the probe sensing region with hydrofluoric acid. Due to the large surface area of the gold nanoparticles (AuNPs), likely to occur in the surface chemical reaction, which can be used to capture and recognize tyramine molecules. Therefore, AuNPs are immobilized on the surface of COF to further improve the sensitivity of the tyramine sensor probe. Tyrosinase enzyme is used to enhance the sensitivity of the sensor probe. The performance of the COF fiber sensor is tested by analyzing the transmitted intensity of the sensor. The experimental results demonstrate that the COF-based biosensor provides a good strategy for clinical applications.
KEYWORDS: Microwave radiation, Signal detection, Reflection, Optoelectronics, Oscillators, Microwave photonics, Signal generators, Tunable filters, Single mode fibers, Laser frequency
We can achieve a high frequency with a low-phase-noise microwave photonics signal with the help of an optoelectronic oscillator (OEO). In this paper, we propose an OEO based on an external modulator and a dispersive component that provides frequency selection properties similar to those of the photonic filter, i.e. π phase-shifted fiber Bragg grating (π PS-FBG), which has a fixed center frequency of 1550nm. By changing the wavelength of an optical carrier signal, we can tune the oscillating frequency of the OEO. The π PS-FBG reflected signal was passed through parallelly connected single-mode fibers of 0.1 Km, 0.2 Km, and 0.4 Km length. An extra delay in the loop is provided for locking the oscillating frequency. we use π PS-FBG filters designed for the wavelengths 1550 nm to 1555 nm and the corresponding frequency of oscillation was observed between 4.63 GHz and 40.17 GHz. We make observations of the oscillating frequency. With the help of simulated results, the overall model has been theoretically analyzed and verified.
In this work, a novel microwave photonic approach is applied to generate an arbitrary chirp microwave waveform in the Ku band that possesses a high chirp rate. Chirp microwave signals can be produced in a variety of ways, the most common of which is the shaping of the temporal pulse and the mapping of the wavelength to the time. The usage of Kuband frequencies is widespread in modern radar applications, such as high-resolution mapping and satellite altimetry. The range-Doppler resolution of a radar system can be enhanced by improving its chirp rate, time-bandwidth product, and center frequency. The proposed approach in this work is based on the direct modulated Laser source and polarization controller. The theoretical and simulation analysis has been done to generate a dual linear chirp microwave signal in the Ku band with a center frequency of 12 GHz.
Creatinine is a metabolite of human muscles that can be used to infer whether part of the kidneys is functioning properly. In this paper, a taper-in-taper fiber (TITF) based fiber optic biosensor is proposed for detecting the concentrations of creatinine solution and helps to diagnosis of kidney failure. The TITF structure used in this study is formed by fabricating a taper shape again in the tapered region of a normal taper optical fiber. This allows the fiber to produce more higher-order modes and thus improve its ability to sense changes in refractive index of the external environment. The sensitivity of the sensor was increased by coating the tapered region of the TITF fiber with a gold nanoparticles and zinc oxide nanomaterials. Creatinase enzyme is used to increase the specificity of the sensor for creatinine. The experimental results show that the sensor can detect the creatinine solution with the concentrations of 300-2000 μM and the sensitivity is 0.17 a.u./μM. It provides a good choice for biomedical applications.
In this study, a novel optical fiber sensor based on varying cladding diameters is developed to detect different tyramine concentrations. Single-mode fiber (SMF, 8.25/125 μm) and multimode fiber (MMF, 200/220 μm) are fused to form the SMF-MMF-SMF structure. The output signal is amplified by etching the fiber sensing region that can generate stronger evanescent fields. Multi-walled carbon nanotubes (MWCNTs) are used to enhance the sensing performance. The tyramine enzyme is used to functionalize the probe and realize the specificity of the probe for tyramine. The performance of the sensor is analyzed, and results show that the sensor has good selectivity. The results also show that the sensors based on different cladding diameters can be used as special sensors for measuring the concentration of tyramine.
The current study proposes a lossy mode resonance (LMR) sensor for ascorbic acid detection. LMR sensors are significant in the field of biosensing because of their high sensitivity, specificity, and versatility. The detection of proteins in blood or other biological fluids, DNA hybridization in genetic testing, and bacteria or viruses in environmental or clinical samples are all applications of the use of LMR sensors in biosensing. With the ability to detect biomolecules with enhanced performance, the use of nanomaterials in biosensing has the potential to revolutionize the area. It can have substantial effects on identifying diseases, developing new drugs, and environmental monitoring. With graphene oxide (GO), a novel SMS (single mode fiber-multi mode fiber-single mode fiber) structure has been developed to detect ascorbic acid. GO nanoparticles have been used in this work over an etched optical fiber for higher sensitivity. Experimental testing is done to determine the sensor's effectiveness in the detection of the analyte.
KEYWORDS: Spatial light modulators, Orthogonal frequency division multiplexing, Transmitters, Modulation, Signal detection, Data transmission, Receivers, Wireless communications, Systems modeling, Telecommunications
Optical Wireless Communication (OWC) has the potential to offer a transmission link that is both dynamic and flexible in comparison to fiber optics communication. The optical spectrum exhibits a significantly greater range than the conventional Radio Frequency (RF) communication spectrum. Optical Orthogonal Frequency Division Multiplexing (OOFDM) can be treated as an integral part of OWC Systems. It is a modulation technique which refers to the implementation of OFDM in the Optical Domain. For the OFDM signal to be transmitted in the Optical domain, we perform Intensity Modulation/Direct Detection and for that the signal needs to be real and positive. In this paper, we have made the signal Hermitian symmetric along with IFFT and performed adaptive biasing to make the transmitting signal real and positive respectively. One of the major issues which still persists is the high Peak-to-Average Power Ratio (PAPR). To overcome this, we have implemented Selected Mapping (SLM), using Shapiro-Rudin Phase Sequences (SRPS). We have used SRPS as they yield a low crest factor, have good randomness, strong correlation, and help in reducing the average transmit power, which will eventually help in decreasing the complexity of the system. By performing Adaptively Biased Optical OFDM (ABO-OFDM) in conjugation with SLM we have been able to achieve a reduction of about 3 dB in the PAPR graph, without affecting the BER curve. Moreover, the increase in the system complexity is comparatively lower, or it can be stated that the increase is approximately halved.
KEYWORDS: Signal to noise ratio, Free space optics, Receivers, Turbulence, Transmitters, Telecommunications, Modulation, Laser sources, Systems modeling, Forward error correction
In free space optical communication (FSO) communication, it is assumed that the fading due to atmosphere turbulence (AT) is uncorrelated at the receiver. But, in practice the spacing between the receivers is less than the fading correlation length. So, we have to consider a correlated statistical model for FSO AT model. In this paper, we have analyzed space shift keying (SSK) modulation scheme over correlated Gamma-Gamma (GG) fading model. We have derived an average bit error rate (ABER) using moment generating function (MGF) for space shift keying modulation scheme over correlated Gamma-Gamma (GG) fading model. The system is analyzed for different atmospheric conditions, correlation values and different number of receivers. It can be observed that as we increase the correlation value, the ABER value deteriorates. It can be observed that the ABER does not depend on turbulence at low SNR, but for high SNR the ABER performance improves and the ABER performance is approximate same in weak and moderate turbulence. However, the difference of SNR between moderate and strong turbulence is approximate 5 dB for ABER value of 10−4. We note that at a given SNR, the ABER improves as we increase the number of receivers. Also, it can be observed that the ABER deteriorates as correlation increases for same number of receivers. We have also analyzed the system both uncoded and LDPC coded SSK transmitter systems. It is observed that for ABER value of 10−4, the SNR difference between LDPC coding and without encoding is approximate 3 dB.
This article presents a lossy mode resonance (LMR) phenomenon based single mode fiber (SMF) structure for the detection of ascorbic acid (vitamin C). The fiber was etched for specified duration and then analyzed for Ascorbic acid detection. Ascorbic acid belongs to the group of drugs known as antioxidants. The body need it to boost the immune system, promote wound healing, and improve the absorption of iron from plant-based meals. The ascorbic acid test is useful for rapidly determining the levels of naturally occurring vitamin C in meals like fruit and vegetable juices etc. It can also be used to determine amount of ascorbic acid present in particular foods as a preservative or antioxidant. The proposed SMF structure will be used for the detection of ascorbic acid using graphene oxide (GO).
This manuscript aims to analyze the effect of bariumtitanate (BaTiO3) and molybdenumdisulfide (MOS2) along with gold (Au) on the sensing application of surface plasmon resonance (SPR) biosensors. The proposed multilayer structure has a BK7 prism, a bimetallic layer of Au, BaTiO3, and a MOS2 layer. BaTiO3 and MOS2 layers are used to improve the biosensor performance parameters by the Kretschmann configuration. The proposed configuration has enhanced the performance over the conventional sensor. The performance parameters like full width half maximum (FWHM), detection accuracy, and detection accuracy have been analyzed. The suggested biosensor can detect a wide range of analytes with an extensive refractive index range. The proposed sensor can be used to analyze chemical and biological analytes.
Surface plasmon resonance (SPR) sensors are extensively used in a variety of applications. In the proposed investigation, SPR phenomena are used to detect toxic gases by employing a multilayer sensing chip. A glass prism is coated with a nano composite thin film based on different materials: gold (Au), titanium dioxide (TiO2), and molybdenum disulfide (MoS2). The ammonia gas is applied to the MoS2 sensing layer of the multilayer optical sensing chip. As the ammonia gas concentration rises around the multilayer sensing structure, the resonance angle increases, indicating that the MoS2 layer refractive index has gone up significantly due to absorption of the increasing ammonia gas concentration. The measured ammonia gas concentration is based on an angle interrogation approach. The sensor performance has also been optimized for varied MoS2 and Au layer thicknesses. This article has all the mathematical equations that are needed, and MATLAB software is used to check the results.
Food adulteration is a global concern, and developing countries are under serious threat owing to a lack of supervision and laws. Specially, milk adulterants can cause severe health risks, resulting in fatal diseases. Conventional and qualitative detection techniques are limited due to the more sophisticated way of milk adulteration and involve complexity in the processes. This paper used ultraviolet-visible-near infrared (UV-Vis-NIR) spectrophotometric measurements technique to detect the urea concentration in the milk sample. Urea concentration was taken initially at the steps of 5% and then with 10% to mix with pure milk to measure the adulteration. Results showed that the absorbance spectrum increased proportionally in the Vis and NIR regions when we increased or added the amount of urea to milk. The proposed spectrophotometry method will be a successful basis for the screening of optical wavelength to help the researcher to find out the surface plasmon resonance (SPR) phenomenon where the light and matter interaction is maximum.
This experimental work presented the reduced graphene oxide (rGO) immobilized etched fiber Bragg grating (eFBG) sensor to improve refractometric sensitivity. The effectiveness of the proposed sensor is evaluated with cigarette smoke as well as incense smoke by monitoring the shift in the resonant peak of the reflection spectra of the sensor with the interrogator. An increase in the interaction of the evanescent field adsorbing with the smoke caused by the rGO layer increases the sensing performance. Raman spectroscopy, XRD, and field emission scanning electron microscope are used for characterization of the sensor.
Prism-based surface plasmon resonance (SPR) optical sensors are extensively used in a variety of applications. In implementing a multilayer sensing structure, SPR phenomena are employed to detect gases in the proposed research. A BK7 glass prism is used as a sensing structure with decomposition on nano thin films based on different materials: silver (Ag), titanium dioxide (TiO2), and graphene. The methane gas is applied to the graphene sensing layer of the multilayer optical sensor. As the methane gas concentration rises around the sensor, the SPR angle varies, indicating that the refractive index of graphene layer is changed significantly due to absorption of the increasing methane gas concentration. The methane gas concentration measurement is based on an angle interrogation technique. TiO2, graphene, and Ag layers of different thicknesses have been optimised for sensor performance.
Dopamine, an important neurotransmitter, can play both excitatory as well as inhibitory role in human body by either exciting the receptors on postsynaptic membrane or by inhibiting or suppressing them. It plays crucial roles in the working of renal, central-nervous, hormonal and cardiovascular system. An elevated level of dopamine results in cardio-toxicity that leads to rapid increase in heart rates, hypertension, drug addiction and heart failure. The low level of dopamine, on the other hand, may cause stress, depression, ailments such as schizophrenia, Alzheimer's disease, Parkinson's disease and many more. Thus, monitoring of dopamine measures in body in real time is vital for observing its impact on biological process and mechanism. In this work, a straightforward and efficient sensor model is proposed to detect the presence of dopamine in human body. Etched optical fiber with an overlayer of one of the most promising 2D material-graphene oxide (GO) is used for developing the sensor with the lossy mode resonance (LMR) approach. The sensor probe was analyzed for its performance in terms of stability. The experimental results show that the proposed etched LMR biosensor has immense capacity to sense the presence of dopamine in human and thus have significant application in real time detection and monitoring of dopamine.
In this work, mathematical models of surface plasmon resonance (SPR) biosensors are proposed. The proposed sensor with transition metal dichalcogenides (such as PtSe2) constructed of two-dimensional materials (BP and WS2). Traditional SPR biosensors are also discussed. In the field of SPR sensors, researchers have been very interested in 2-D materials. Figure of merit (F.O.M) and sensitivity are two important parts of SPR sensors, and it has been talked about with analyte ranges from 1.330 to 1.36. The proposed sensor was found to be most sensitive when it had just one layer of Platinum diselenide (PtSe2) and two layers of black phosphorous (BP). Here, a heterostructure made of BK7 Prism/Ag/PtSe2/WS2/BP is proposed as a much sensitive SPR biosensor with a Kretschmann configuration at a wavelength of 633 nm. The attenuated total reflection (ATR) method is used to measure the sensors' sensitivity, figure of merit (F.O.M.), Minimum reflections (Rmin) and detection accuracy (D.A). The proposed sensor has many uses in biomedical, chemical, and bio-sensing fields.
In the next fifth-generation (5G) and sixth-generation (6G) wireless cellular networks, the millimeter-wave band presents new possibilities for extremely strong data transfer speeds and extensive network connectivity. Millimeter waves, on the other hand, suffer from a large loss of propagation, which is the most severe obstacle. Utilizing beamforming with several antennas is a helpful solution to this problem, which may be overcome. In this article, a concept for an integrated photonic beamforming system is presented using ring resonator for 1 4 phase array antenna in Ka-Band. Signal operating at 28GHz is based on waveguide technology. The micro-ring resonator is utilized so that the actual time delay line can be achieved. The mathematical analysis and design of the beam forming structure are presented after that It was possible to produce a group delay of 250 ps, 500 ps, 750 ps, and 1000 ps delay of the proposed different cascaded architecture of ring resonator as a delay element which corresponds to a beam directing angle of 30° , 90° , 11.5° , 8.62° degrees respectively.
By employing a delay line signal processing technique, a mathematical model of an asymmetrical quad microring resonator (QMRR) can be calculated. Four asymmetrical rings are coupled with each other in vertically connected structures of QMRRs are designed. The performance of QMRR structures is demonstrated using two different types of waveguide bus, namely crossing and parallel waveguides. In the MATLAB environment, the frequency spectrum response and accompanying transmittance, phase, and group delay plots are programmed and graphically presented.
This paper presented a sensitivity analysis of petrol adulteration. The benzene and xylene are mainly used as adulterants in petrol because of their low cost and easy miscibility. In comparison to traditional methods, the proposed etched fiber Bragg grating (eFBG) sensor is able to detect up to low-level adulteration efficiently when coated with a TiO2 layer. Adulteration in benzene-petrol and xylene-petrol is detected using concentration mixing with 10% increments in each case. The experimental outcomes of sensitivity and Bragg wavelength shifting were studied. TiO2-coated eFBG sensors achieved the sensitivities of 6.2 nm/RIU and 5.6 nm/RIU, which is 7% and 5% enhanced as compared to bare eFBG sensors in the case of benzene-petrol and xylene-petrol, respectively. This type of sensor is well-suited for on-road use in real-time.
In the proposed work, titanium dioxide (TiO2) coated on an etched fiber Bragg grating (eFBG) sensor has been used for sensing the industrial chemicals such as glycerin. The FBGs were etched with hydrofluoric acid at a 40% concentration to interact with the outer medium before applying an optically active thin material layer for improved sensing. Raman spectroscopy and FESEM are used to characterize the sensor. An increase in the interaction of the evanescent field interacting with the analyte caused by the metal oxide layer increases sensitivity by approximately 24%. The sensitivities achieved with the bared eFBG sensor and the TiO2-coated eFBG sensor are 10.18 nm/RIU and 13.4 nm/RIU, which is better than any other earlier reported work for sensing glycerin.
Ascorbic acid, genreally known as Vitamin ‘C’, is a nutrient, which is responsible for numerous biological functions like collagen formation, iron absorption, growth and repair of cells, tissues, bones, cartilages, teeth etc. It plays a promising role in providing a healthy immunity against bacterial and viral infections. It also helps in making several chemical messenger and hormones, thus playing importance in the nervopus system of body. Thus, ascorbic acid is a biomarker for the detection of various malfunctionings of the body like weakened immunity, scurvy, cardiovascular diseases, Alzheimer’s and Parkinson’s disease. In this work, a straightforward and effectual sensor model is proposed to detect the presence of ascorbic acid samples found in human body. Etched single mode fiber-multimode fiber-single mode fiber (E-SMS) is used for developing the sensor with the application of localized surface plasmon resonance (LSPR) phenomenon. For achieving LSPR and better sensitivity, the E-SMS are coated with gold nanoparticles (AuNPs). The different concentration of ascorbic acid solution alters the refractive index and the spectrum thus recorded and evaluated. The experimental results shows that the proposed E-SMS-based LSPR biosensors can detect the presence of ascorbic acid in human body and thus have significant application in the field of biosensing.
Cholesterol plays an important role in biological systems, and the quantity of cholesterol in the human body serves as a diagnostic marker for a range of disorders. This article presents a localized surface plasmon resonance (LSPR) sensor based on dual-tapered optical fiber (DTOF) that can detect cholesterol levels in the human body. To stimulate the LSPR effect and increase the sensitivity of the sensing probe, gold nanoparticles were fixed on the DTOF’s surface. In this study, the reaction between cholesterol and cholesterol oxidase altered the refractive index near the sensing probe, and the related spectrum was obtained. In addition, the sensor’s performance, including linear range, repeatability, reusability, stability, and selectivity, was examined. The experimental results indicate that the proposed DTOF-based LSPR sensor is capable of reliably measuring cholesterol levels and has promising biomedical applications.
The detection of glucose level in human body is very necessary for motoring physical condition. In our work, a triple tapered sensor probe based localized surface plasmon resonance (LSPR) is developed to detect various glucose concentration solution. The single-mode fiber (SMF) is utilized to prepare the proposed triple tapered structure. The serial taper structure in the sensing area insure more evanescent wave (EW) leak out. Gold nanoparticles (AuNPs) are modified on the serial triple tapered fiber (STTF) structure to stimulate the LSPR phenomenon. The limit of detection (LOD) and sensitivity of sensor are 3.8 mM and 0.59 nm/mM, respectively. Moreover, the reproducibility, selectivity, pH test, and reusability of STTF probe are evaluated to validate the ability in practice.
This study designs an optimal optical 1 to 2 data distributor using a nonlinear optical effect within metal–insulator–metal plasmonic (MIM) waveguides based on the Mach–Zehnder interferometer. An optical source of 1550 nm and FDTD technique are utilized to design and simulate the proposed structure. The FDTD results are then validated using a MATLAB simulation of the design. The proposed design can be used in high-speed combinational circuits to distribute a given data to 2n users.
Optical gadgets will take the role of electronic devices in the following decade due to their fast speed, low power consumption, and low heat tolerance. As a consequence, photonic crystal (PhC) based all-optical Buffer, AND, and OR (BAO) logic gates (LoG) were constructed by exploiting square lattice silicon rods with an air background. The suggested LoGs function efficiently by altering the phase of light beams having a wavelength of 1550 nm and are working on the beam-interference principle. The structure is modeled and tested through the finite-difference time-domain (FDTD) approach. For each logic gate, the performance parameter of extinction ratio (ER) is determined by tweaking the silicon rod radius and refractive index over a set of parameters. The suggested all-optical BAO LoG has extinction ratios of 11.84 dB, 33.9 dB, and 11.65 dB, respectively. The response time and operating speeds for each input combination are also calculated and tabulated.
In this study, a plasmon sensor based on a core mismatch optical fiber structure is proposed for measuring various creatinine concentrations. Creatinine is an important clinical biomarker for diabetes, kidney disease, renal failure, and muscle atrophy. The single-mode fiber (SMF) and multi-mode fiber (MMF) are used to fabricate the SMF-MMF-SMF-MMF-SMF (SMSMS) structure. Further, SMSMS fiber structure is etched with hydrofluoric (HF) acid, that results in more evanescent fields at the core-cladding interface. Gold nanoparticles (AuNPs) are immobilized on the surface of the optical fiber structure to activate the LSPR phenomenon. To validate the sensor's performance, the sensor's sensitivity, reusability, reproducibility, and selectivity are tested. The experimental results demonstrate that the fiber-optic sensor based on the SMSMS structure is capable of measuring creatinine concentrations over a wide range in aquaculture industry. This provides an excellent opportunity for the sensor to be used in biomedicine.
Cholesterol plays a very important role in human physiological function, and the level of cholesterol in human body is a marker for diagnosing a variety of diseases. The article proposes a localized surface plasmon resonance (LSPR) sensor based on dual-tapered optical fiber (DTOF) that can detect cholesterol concentrations in the human body. To excite the LSPR effect and improve the sensing probe's sensitivity, gold nanoparticles (AuNPs) were immobilized on the surface of the DTOF. In this work, the specific reaction between cholesterol and cholesterol oxidase led to the change of refractive index (RI) near the sensing probe, and the corresponding spectrum is collected. Additionally, the performance of the sensor was evaluated, including linear range, reproducibility, reusability, stability, and selectivity. The experimental results demonstrate that the proposed DTOF-based LSPR sensor is capable of detecting the cholesterol level accurately and has a promising application in biomedicine.
Reflecting codes are frequently employed to reduce erroneous output from electromechanical/optical switches and to assist error correction in today’s communication systems such as digital terrestrial television and some cable TV systems. In this work, all optical reflective code is designed and simulated using a nonlinear optical effect inside metal-insulator-metal plasmonic waveguides based on Mach–Zehnder interferometer. Finite-difference time-domain (FDTD) method is used to analyze the performance of proposed structure and results are verified with MATLAB simulation.
In this work, an optimized all-optical 2x1 line selector is designed and simulated using a nonlinear optical effect inside metal-insulator-metal plasmonic waveguides based Mach–Zehnder interferometers. The proposed design is simulated using an optical source of 1550 nm and obtained the results by finite-difference time-domain (FDTD) method and results are verified with MATLAB simulation.
In this paper, localized surface plasmon resonance (LSPR) based tapered multimode optical fiber (TMMF) sensor is developed for the detection of different concentrations of p-cresol solutions. Gold nanoparticles (AuNPs) and molybdenum disulfide nanoparticles (MoS2-NPs) were immobilized on TMMF probes, respectively. The performance of the designed probe was explored by detecting the response of different concentrations of p-cresol solutions. The combination of AuNPs and MoS2-NPs enhances the sensitivity and anti-interference ability of the sensing probe. In this work, the enzymatic reaction of p-cresol solution and tyrosinase changes the RI in the vicinity of the probe and records the corresponding spectrum. The probe will also be evaluated in terms of linear range, limit of detection (LoD), reproducibility, reproducibility, stability, selectivity, etc.
The core mismatch formed by the splicing of different fiber cores and tapered fiber is beneficial to the sensing. In this paper, a single-mode fiber (SMF)- tapered multi-mode fiber (tapered MMF)-single-mode fiber structure was fabricated and used as a sensor to detect uric acid. The gold nanoparticles (AuNPs)/zinc oxide (ZnO) nanoparticles were fixed on the tapered surface to enhance the localized surface plasmon resonance (LSPR) and its sensing performance. The experimental results show that the optical fiber sensor can detect different concentrations of uric acid solution successfully and has a linear response in a certain range for biomedical applications.
In this work, a simple and effective sensor using single-mode fiber (SMF) tapered structure is developed to detect different concentrations of acetylcholine solutions, and its function is to test the probe's performance. A layer of synthesized gold nanoparticles (AuNPs) and zinc oxide nanoparticles (ZnO-NPs) is used to immobilize this type of SMF-based tapered structure. The work is based on the well-known phenomenon of localized surface plasmon resonance (LSPR) principle. A tapered region of the probe with a high fraction power of evanescent wave can stimulate LSPR and produce specific absorption peaks sensitive to the refractive index variation. The sensor probes performance was examined, including their stability, repeatability, reusability, and selectivity. Furthermore, the biosensor's ability to improve performance was tested in the experiment.
All-optical photonic integrated devices have gained great attention in the field of optical computing and large-scale integration. All-optical logic gates are useful for optical signal processing and optical communication network. The flexible devices presented here satisfy the functionality of NAND (NOT-AND), NOR (NOT-OR), and XNOR (exclusive NOR) logic gates using only one structure with proper changes in the phase of an applied light signal. The design of all-optical logic gates is implemented with photonic crystal waveguides using square lattice silicon rods. The performance of the structure is simulated, verified, and analyzed by the finite-difference time-domain method, with the principle of interference effect at a wavelength of 1550 nm. The contrast ratio (CR) of NAND, NOR, and XNOR logic gates is 17.59, 14.3, and 10.52 dB, respectively, with an optimized size of 7.2 μm × 5.4 μm.
The deterioration of environmental conditions decreases the quality of people lives permanently. The prime reason in mortality of people lives in industrial developing countries is disease related to blood circulation system. In this work, monitoring of blood protein i.e. fibrinogen is done by double slot hybrid plasmonic waveguide. The concentration of fibrinogen increases rapidly during various inflammatory processes. The fibrinogen is a type of protein which is found in blood coagulation system, which is the main factors of many cardiovascular diseases in human.
A microring resonator based sensor is proposed to detect different poisonous gases, such as carbon monoxide, phosphine, and nitrogen dioxide. These gases are very dangerous in environment if the leakage concentration is high. The single slot microring resonator sensor is used for detection of hazardous gases. The sensor has been analyzed through finite-difference-time-domain method by varying the radii of microring resonator from 1.4 μm to 2.2 μm and refractive index of the analytes. Transmission of microring resonator is observed and detected the different poisonous gases.
A code is said to be an error-correcting, if the correct code word can always be deducted from an erroneous word. Hamming code is most suitable for error detection and correction for digital data. It facilitate error detection and correction in code information. Here 7 bit Hamming code convertor is proposed. In this code, to each group of m information bits, n parity checking bits are located at positions 2(n-1) from left are added to form an (m+n)-bit code word. Code convertor device is designed using Mach-Zehnder interferometer (MZI). MZI is an optical switch, able to transfer signal from one port to other.
This work is based on surface plasmon (SP’s) confinement in nano-slots of double slot ring resonator structure, which can employ for diverse liquid sensors and cause of anemia in homosapiens. The structure is depicted using hybrid plasmonic waveguides (HPW) due to its absolute attribute of longer propagation length of SP’s. The structure of waveguide is delineated in such a way that optical energy is extreme mainly in narrow slots of two metallic layers. The HPW based sensor is used to detect the causes of anemia which is very common and severe almost among every step of age. The compatibility and capability of sensor will be analyzed by calculating its sensitivity, quality factor and figure of merit.
The under laid gas and oil pipelines on the seafloor are prone to various disturbances like seismic movements of the sea bed, oceanic currents, tsunamis. These factors tend to damage such pipelines connecting different locations of the world dependent on these pipelines for their day-to-day use of oil and natural gas. If damaged, the oil spills in the water bodies cause grave loss to marine life along with serious economic issues. It is not feasible to monitor the undersea pipelines manually because of the huge seafloor depth. For timely detection of such damage, a new technique using optical Fiber Bragg grating (FBG) sensors and its installation has been given in this work. The idea of an FBG sensor for detecting damage in pipeline structure based on the acoustic emission has been worked out. The numerical calculation has been done based on the fundamental of strain measurement and the output has been simulated using MATLAB.
In this work, Pd/Pt material based fiber Bragg grating (FBG) sensors has been proposed for detection of hydrogen sulfide gas. Here, characteristics of FBG parameters were numerically calculated and simulated. The variation in reflectivity based on refractive index has been shown. The reflectivity of FBG can be varied when refractive index is changed. The proposed sensor works on very low concentration i.e., 0% to 1%, which has the capability to detect in the early stage.
A plasmonic metal–insulator–metal (MIM) waveguide has great success in confining the surface plasmon up to a deep subwavelength scale. The structure of a nonlinear Mach–Zehnder interferometer (MZI) using a plasmonic MIM waveguide has been analyzed. A one-bit magnitude comparator has been designed using an MZI and two linear control waveguides. The device works on the Kerr effect inside the plasmonics waveguide. The mathematical description of the device is explained. The simulation of the device is done using MATLAB® and the finite-difference time-domain (FDTD) method.
The application of electro-optic effect in lithium-niobate-based Mach–Zehnder interferometer to design a 3-bit optical pseudorandom binary sequence (PRBS) generator has been proposed, which is characterized by its simplicity of generation and stability. The proposed device is optoelectronic in nature. The PBRS generator is immensely applicable for pattern generation, encryption, and coding applications in optical networks. The study is carried out by simulating the proposed device with beam propagation method.
In this ultra fast computing era power optimization is a major technological challenge that requires new computing paradigms. Conservative and reversible logic opens up the possibility of ultralow power computing. In this paper, basic reversible logic gate (double Feynman gate) using the lithium-niobate based Mach-Zehnder interferometer is proposed. The results are verified using beam propagation method and MATLAB simulations.
In this study, J-K flip-flop is proposed utilizing electro-optic effect of lithium niobate based Mach-Zehnder interferometers (MZIs). J-K Flip flop is most versatile flip-flop amid basic flip-flops. It has vast applications in data storage, data transfer, frequency division, binary counters etc. Lithium niobate (LiNbO3) based MZIs provide both the required bandwidth and the equally important means for minimizing the effects of dispersion. The work is carried out by simulating proposed device with Beam propagation method. The paper also constitutes the mathematical description of device and thereafter simulation using MATLAB.
The all optical routing is novel approach for establishment of transparent information flow in optical networks. The diffraction limit of light is major factor which backseats the photonic components and mitigated by integrated all optical components. In this paper, an all-optical signal router with two optical inputs using nonlinear plasmonic Mach-Zehnder interferometer (MZI) is proposed. The nonlinearity in MZI structure is achieved by using nonlinear Kerr-material, which is also responsible for switching of optical signal across two output ports. The study of proposed device is carried out using finite-difference-time-domain (FDTD) method and verified using MATLAB.
MIM plasmonic waveguides are considered in proposed work, due to their ability of confining the surface plasmons to deep subwavelength scale or beyond diffraction limit. By cascading various MIM waveguides Mach-Zehnder interferometer (MZI) is designed which has been used to design all-optical 3 × 8 line decoder. To attain the nonlinearity Kerr material has been used. The proposed device is studied and analyzed using finite-difference-time-domain (FDTD) method and MATLAB simulations.
An optical 3-bit Excess-3 code converter is demonstrated by using Mach-Zehnder Interferometers based on electro-optic effect. It is a way to represent values with a balanced number of positive and negative numbers using a prespecified number N as a biasing value.
In this paper, an effective design of all-optical logic gates like XOR gate and AND gate is presented. The structure of these two logic gates is based on T-shape waveguide with optimized silica dielectric rod. Along with the two input ports which are essential for the required logical operation, an extra reference input port is used. These two logic gates can be used to construct for various combinational logic circuits, data bit comparison circuits, pattern matching, data encoding/decoding and different switching functions etc.
Seven-segment decoder is a device that allows placing digital information from many inputs to many outputs optically, having 11 Mach–Zehnder interferometers (MZIs) for their implementation. The layout of the circuit is implemented to fit the electrical method on an optical logic circuit based on the beam propagation method (BPM). Seven-segment decoder is proposed using electro-optic effect inside lithium niobate-based MZIs. MZI structures are able to switch an optical signal to a desired output port. It consists of a mathematical explanation about the proposed device. The BPM is also used to analyze the study.
In recent years, it has been shown that reversible logic can play an important role in power optimization for computer design. The various reversible logic gates such as Feynman, Fredkin, Peres, and Toffoli gates have been discussed by researchers, but very little work has been done on reversible sequential circuits. Design of reversible sequential circuits using lithium-niobate-based Mach–Zehnder interferometers is proposed. Here, flip-flops are designed with the help of basic reversible logic gates such as Feynman, Fredkin, and Peres gates. Theoretical descriptions along with mathematical formulation of the devices are provided. The devices are also analyzed through finite difference-beam propagation method and MATLAB® simulation.
Optical 1’s and 2’s complement devices are proposed with the help of lithium-niobate-based Mach–Zehnder interferometers. It has a powerful capability of switching an optical signal from one port to the other port with the help of an electrical control signal. The paper includes the optical conversion scheme using sets of optical switches. 2’s complement is common in computer systems and is used in binary subtraction and logical manipulation. The operation of the circuits is studied theoretically and analyzed through numerical simulations. The truth table of these complement methods is verified with the beam propagation method and MATLAB® simulation results.
With the demand of ultrahigh-speed logic, there has been an emphasis on low-power design techniques. Reversible computing has been proposed as a possible alternative to address the energy dissipation problem. Thus, the reversible circuit implementation in optical domain gives a new dimension in ultrahigh-speed, low-power consumption of quantum computing. In this study, a design of reversible multiplexer using electro-optic effect of lithium niobate-based Mach–Zehnder interferometer is proposed. It is verified using a beam propagation method along with MATLAB simulation.
The efficient application of electro-optic effect in lithium niobate based Mach-Zehnder interferometer (MZI) to construct the temperature sensor is used. An experimental set up for liquid temperature sensor is proposed. Temperature dependence of the bending loss light energy in multimode micro-plastic optical fiber (m-POF) and electro-optic effect of MZI are used. The performance of sensor at different temperatures is measured. It is seen that the light output of MZI switches from one port to the other port as temperature of liquid changes from 0°C to 100°C.
Encoder is a device that allows placing digital information from many inputs to many outputs. Any application of combinational logic circuit can be implemented by using encoder and external gates. In this paper, 4 to 2 line encoder is proposed using electro-optic effect inside lithium-niobate based Mach-Zehnder interferometers (MZIs). The MZI structures have powerful capability to switching an optical input signal to a desired output port. The paper constitutes a mathematical description of the proposed device and thereafter simulation using MATLAB. The study is verified using beam propagation method (BPM).
Excess 3 code is one of the most important codes used for efficient data storage and transmission. It is a non-weighted code and also known as self complimenting code. In this paper, a four bit optical Excess 3 to BCD code converter is proposed using electro-optic effect inside lithium-niobate based Mach-Zehnder interferometers (MZIs). The MZI structures have powerful capability to switching an optical input signal to a desired output port. The paper constitutes a mathematical description of the proposed device and thereafter simulation using MATLAB. The study is verified using beam propagation method (BPM).
In this paper, an optical finite impulse response (FIR) filter is proposed. An optical FIR filter can produce arbitrary spectrum output based on transfer function. The corresponding relationship between an optical filter and FIR filter is analyzed and analysis is presented in detail.
The limitation of conventional electronics is mitigated by all optical integrated circuits which have potential of high
speed computing and information processing. In this work, an all optical AND gate using optical Kerr effect and optical
bistability of a plasmonic based Mach-Zehnder interferometer (MZI) is proposed. An MZI is capable for switching of
light according to the intensities of optical input signal. The paper constitutes with mathematical formulation of device
and its study is verified using finite difference time domain (FDTD) method.
Photonic Crystal Fibers (PCFs) have special structures and offer a number of novel design options, such as very large or very small mode areas, high numerical aperture, guidance of light in air, and novel dispersion properties. PCFs have become an attractive field for the researchers and they are trying to work on these to get their properties applied in dispersion related applications, sensing applications and much more. PCFs sensors are widely used in bio-medical applications. The sensitivity and performance of sensors are enhanced due to novel applications of PCFs. This paper outlines a novel design for a generalized biomedical sensor by collaborating PCF and electro-optic effect of Lithium Niobate (LiNbO3) based Mach-Zehnder interferometer (MZI) structure.
In this paper, dispersion equation of optical waveguide using metamaterial as buffer layer with non-linear cladding and substrate is pointed. The sensitivity of TE in metamaterial optical waveguide sensor is computed mathematically. The impacts of buffer layer with non-linear cladding and substrate on metamaterial optical waveguide sensor are also tried out. The effects of various parameters on sensitivity of sensor are obtained through MATLAB. It is expected that metamaterial as buffer layer with non-linear cladding and substrate profile has a huge application in leaky fibre sensor, gas sensor and chemical sensor for oil and under grounds mining industries.
Micro-ring resonators are important devices applicable for optical filtering phenomena. The paper provides the detailed description of general characteristics of serially coupled multiple ring resonator (SMRR). The identical perimeters and coupling coefficients provides the pass band characteristics with flatter top. The paper includes the concept of Masons gain formula and its application in order to analyze the transfer characteristics of single and multiple ring resonator structures. The graphical approach provides the fast derivation of transfer function of SMRR. The results are properly verified with the MATLAB.
The optical switching phenomena have been contemplated and the Mach-Zehnder interferometer (MZI) structure is used for the implementation of the optical AND gate. The cogitation of various factors such as crosstalk, extinction ratio, power imbalance and transition loss has been presented. The contemplation is carried out by simulating the proposed device with Beam propagation method and using the observed results to study the characteristics of influencing parameters in consideration with the device parameters.
The efficient application of the Mach–Zehnder interferometer (MZI) structure for the construction of the well-known logic gates is described. It deals with the effect of the varying voltages of each electrode on the performance of MZI. It has been found that power transmission gets switched with the variation of voltage in the electrodes. The results are of prime importance for optical gate implementation as well as being useful in the signal router. There is a commercial demand of optical gates and signal routers in dense wavelength division multiplexing. The result is also verified by proper analysis using OptiBPM and matlab softwares.
A real time multichannel dynamic erbium doped fiber amplifier (EDFA) Simulink model with flat gain and gain clamping facility has been developed on a MATLAB platform. We model the EDFA simulator with one-dimensional nonlinear differential equation that describes the time dependent population density. For the model to show gain flattening multiplexed channels at different wavelengths, the MATLAB function block is used. Next, to simulate the noise performance of EDFA. New forward amplified spontaneous emission (ASE) noise blocks are designed that add noise dynamically at signal wavelength. The model has been implemented in the study of performance characteristics of an EDFA in both C - and L -band signal amplification by simulation. Based on the designed ASE generator, noise figure for different signal wavelengths are calculated. For 980 nm pump power, the noise figure almost reaches the practical limit of 3 dB whereas for 1480 nm pump power, a variation of about 1.5 dB and 0.8 dB is observed from the practical limit for the C - and L -bands, respectively. The present model can be implemented successfully as a test bed in the study of EDFA gain dynamics over the entire third optical communication bandwidth (1525 to 1690 nm) in signal amplification.
This paper presents an overview of integrated optical signal routing based on the principle of electro-optic effects. There are some specific types of materials whose refractive index changes due to the application of the electric field. Lithium-niobate (LiNbO 3 ) and gallium arsenide are some important electro-optic materials. Due to the application of the voltage across electrode present in one of the arms of Mach-Zehnder interferometer (MZI), the electric field changes, hence, phase change in the signal present in one of the arms. Depending upon the phase change introduced, signal shifts from one waveguide to the other waveguide. Hence, this paper provides the detailed description of 1×4 signal router, using three MZI, and its construction using beam propagation method. Finally, the results are verified by the MATLAB-based results.
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