This PDF file contains the front matter associated with SPIE Proceedings Volume 9656, including the Title Page, Copyright information, Table of Contents, Introduction, Authors, and Conference Committee listing.

We propose a simple and concise mathematical method based on the Fraunhofer approximation to analyze the imaging characteristics of slit for broadband light sources. Taking Gaussian-shaped ultra-short laser pulse for example, we investigated the diffraction imaging characteristics of ultra-short light sources through a single-slit and a double-slit. We deduced the mathematical expressions of the intensity distribution of far-field diffraction, and conducted numerical calculation and analysis. It turns out the pulse width of the ultra-short light source plays an important role in the diffraction imaging characteristics of slit. We also provide a quantitative criterion to measure the deviation in terms of far-field diffraction intensity distribution between broadband light source and the ideal monochromatic light source.

In order to improve the measurement accuracy of the angle and signal processing speed of operation, this paper proposes a novel method of second harmonic measurement of multi-beam laser heterodyne for the angle, which based on the combination of Doppler effect and heterodyne technology, loaded the information of the angle to the frequency difference of second harmonic of the multi-beam laser heterodyne signal by frequency modulation of the oscillating mirror, which is in the light path. Heterodyne signal frequency can be obtained by fast Fourier transform, and can obtain values of the angle accurately after the multi-beam laser heterodyne signal demodulation. This novel method is used to simulate measurement for incident angle of standard mirror by Matlab, the obtained result shows that the relative measurement error of this method is just 0.5213%.

The planar waveguide in Nd:YAG crystal was produced by the 1.4 GeV Kr ion irradiation at ultra-low fluence of 1.2×10⁹ ions/cm². The propagation loss is measured to be ~2.1 dB/cm at wavelength of 632.8 nm by using the backreflection method. Under optical pumping of 808 nm light continuous wave lasers at 1065 nm have been realized. The maximum output power is 49.3 mW and the slope efficiency is 45.6%.

In this article, we report on the up-conversion fluorescence and laser characteristics at 852nm in Er³⁺-doped silica optical fiber excited at 800nm wavelength band. The possible up-conversion mechanisms involved are theoretical discussed in terms of ground-state absorption, excited state absorption, up-conversion emission energy transfer and cross-relaxation between excited ion pairs and multi-phonon relaxations. Experimentally, the 700~900nm band absorption spectrum and 850nm band spontaneous fluorescence spectrum are measured and studied. By using two bi-directionally pumped LDs (with 800nm and 792nm emission wavelength respectively) and two Fiber-Bragg-gratings (FBG@852nm), an all-fiber based 852nm up-conversion laser system is built to study the lasing characteristics. These results suggest that Er³⁺-doped silica fibers are potentially useful materials for developing up-conversion lasers and optoelectronic devices, especially helpful for the first telecommunication window (at 850nm band) lasers and amplifiers.

A new process of femtosecond laser micromachining with ultrasonic vibration aided is proposed. An ultrasonic aided device has been designed, and the laser micromachining experiments of transparent materials have been carried out. The effects of the ultrasonic vibration with different power on surface quality and the drilling depth have been investigated, and the mechanism of the ultrasonic vibration aided laser machining has been analyzed. After introducing the ultrasonic vibration device, the residue debris on surface of the ablated trench is significantly reduced, and the drilling depth is increased. These results show that, ultrasonic vibration can effectively improve the surface quality of material processing, increase the depth of the drilling hole and promote the processing efficiency of the femtosecond laser.

We report the modulated Cerenkov radiations in a LiTaO₃ waveguide with an annular domain structure. As a result of the continuous rotation symmetry of such a structure, the phase velocity of nonlinear polarization has a wide modulation tolerance. The reciprocal vectors which could be involved in the interaction had a threshold range associated with waveguide parameters. Our experimental results and simulations demonstrated that the radiation intensity had a close relationship with the overlapping between the pump and the radiated wave, which could be decreased by non-collinear reciprocal vectors.

In high-power solid-state laser, initiative pulse shaping can help improve the output laser’s performance. The evaluation for output laser pulse is also incomplete. In this paper, we propose a method of initiative pulse shaping by using arbitrary waveform generator (AWG), and establish a relatively complete evaluation system for the output pulses shape simultaneously. It achieves the super-Gaussian pulse output with high SNR (signal-to-noise ratio). As a consequence, a square laser pulse with pulse adjustable width ~5ns, rising time 197ps is obtained. The power imbalance of the output square pulse is 3.72%. The similarity between the eight-order super-Gaussian pulse and the one we get from experiment reached 99%.

In dual Mach-Zehnder interferometer (DMZI) system, polarization induced phase shift (PIPS) leads to a big location error. Traditional approaches adopt polarization controller (PC) to eliminate PIPS by controlling polarization state (PS) of light source. Through establishing the influence model of input light PS and equivalent polarization parameters of sensing cable on interference signals, an approach using a simplified polarization controller (PC) to obtain high location accuracy is proposed. The simplified PC is composed of a polarizer and a fiber-fused half-wave plate and can provide a linearly polarized light with azimuth angle controlled. Simulation and experiment indicate that the proposed method and PC design not only has capability of eliminating PIPS, but also has the benefits of low cost and easy control.

A ytterbium-doped large mode area PCF sub-picosecond laser oscillator and amplifier system is experimentally studied. The oscillator which combines NPE and SESAM is operating on the all-normal-dispersion regime and the LMA PCF is used as the gain medium. In the CW mode-locking regime, the oscillator directly generates the pulse at the repetition rate of 83.7 MHz while the pulse duration is 960 fs. The double-clad fiber amplifier system directly generates a high average power of 12.53 W with a pulse duration of 4.1 ps corresponding to the pulse energy of 150 nJ and peak power of 36.6 KW after about 3 m ytterbium doped double clad fiber amplification.

We have demonstrated an all fiber, single-frequency 10 ns pulsed high energy and high peak power amplifier. It was capable of reaching 4.6 mJ pulse energy (460 kW peak power) and 2.3 mJ pulse energy (230 kW peak power) respectively for 10 ns pulses corresponding to the repetition rate of 5 kHz and 10 kHz. In the power amplifier stage, we used the large-mode-area fiber to avoid the nonlinear effects such as SBS.

Simulation study of the stability lateral field distribution for a variety of shapes parallel-plane cavity with the Fox-Li numerical iterative method is conducted in this paper, which gives the optical field amplitude distribution and phase distribution after iterating any number of times. After calculation and simulation, we find that the strip cavity needs 245 times iterations to produce a stable field conditions, while rectangular and circular cavity need 103 and 114 times under the same condition. Finally, the user interface for simulating the field distribution of a common parallel-plane cavity is designed, which is conducive to the understanding and extensive application of the theory of laser transverse mode.

In this article, continued fraction improved algorithm was used as a better method. And the recurrence formula scattering coefficient is improved in the form of continued fractions calculation. In this way, the two key functions are recursive forward to solve the Mie scattering coefficient calculation directly in the presence of recursive data overflow problems and avoid the direct calculation of the value of the Bessel function beyond the computer limits the maximum data caused by data overflow problem. For 1.06um laser scattering numerically calculated the scattered light intensity, the scattering and extinction coefficient varies with particle size and refractive index profile parameters. The results showed that the absorption coefficient increases with increasing particle size parameters gradually increased, when after particle size parameter is greater than 10 remained unchanged; scattering coefficient change with particle size parameters periodic ups and downs; the smaller the imaginary part of the refractive index, the greater the scattering coefficient, the absorption coefficient is smaller, it had no effect on the refractive index of the real part of the two coefficients.

Raman spectrometry was employed to study the characteristics of Raman spectra of polyethylene terephthalate (PET), which were treated with sodium hydroxide, sulfuric acid and copper sulfate, respectively. Raman spectra under different conditions were obtained and the characteristics of the Raman spectra were analyzed. The morphology structures were observed under different conditions using Atomic Force Microscope. The results show that the spectral intensity of PET treated with sodium hydroxide is higher than that untreated between 200-1750 cm-1, while the intensity of PET treated with sodium hydroxide is lower than that untreated beyond 1750 cm-1 and the fluorescence background of Raman spectra is decreased. The spectral intensity of PET treated with sulfuric acid is remarkably reduced than that untreated, and the intensity of PET treated with copper sulphate is much higher than that untreated.

In view of the shortcomings of the traditional image mosaic, this paper describes a new algorithm for image mosaic based on the Harris corner. Firstly, Harris operator combining the constructed low-pass smoothing filter based on splines function and circular window search is applied to detect the image corner, which allows us to have better localisation performance and effectively avoid the phenomenon of cluster. Secondly, the correlation feature registration is used to find registration pair, remove the false registration using random sampling consensus. Finally use the method of weighted trigonometric combined with interpolation function for image fusion. The experiments show that this method can effectively remove the splicing ghosting and improve the accuracy of image mosaic.

This paper proposes a fast image mosaic algorithm based on the improved Harris-SIFT algorithm, according to such problems as more memory consumption, greater redundancy quantity of feature points, slower operation speed, and so on, resulting from using the SIFT algorithm in the image matching stage of the image mosaic process. Firstly in the matching stage of the algorithm, the corner point is extracted by using the multi-scale Harris, feature descriptor is constructed by the 88-dimensional vector based on the SIFT feature, the coarse matching is carried out by the nearest neighbor matching method, and then the precise matching point pair and image transformation matrix are obtained by the RANSAC method. The seamless mosaic can be achieved by using the weighted average image fusion. The experimental results show that this algorithm can not only achieve precise seamless mosaic but also improve operation efficiency, compared with the traditional algorithm.

Boron-doped a-Si:H thin films were prepared by plasma-enhanced chemical vapor deposition technique. As-deposited samples were thermally annealed at different temperatures from 450 °C to 1000 °C. The microstructures and electrical properties have been evaluated for the amorphous and nano-crystalline structures. It was found that thermal annealing can efficiently activate the dopant in films accompanying with formation of nc-Si grains. During the transition process from amorphous to nano-crystalline structures, the room temperature dark conductivity is increased from 6.6×10^-4 S cm^-1 to 2.8×10² S cm^-1. Based on the properties of p-type silicon films, the P-N junction solar cells were prepared on n-type nc-Si substrate. It was shown that the conversion efficiency is increased monotonously as increasing the annealing temperature. Form the results, it can be implied that the solar cells with higher conversion efficiency can be obtained by using the method of thermal annealing.

Temperature variations will affect the geometric and optical characteristics of the camera and lens in the videometric system, especially when the optical systems are working in a long period. The paper presents an analysis of the image drift caused by temperature variations and the corresponding temperature compensation method. Firstly, image drift model is established based on the pinhole camera model; then two simplified models are introduced by analyzing the coupling relations between the variations of camera parameters and temperature; furthermore, influence of temperature changes on camera parameters were modeled and calibrated; pose estimation experiments as well as temperature compensations are also conducted in deformation measurements, and the results prove the feasibility and efficiency of the proposed models.

Magnetic sensors utilizing direct magneto-optic field coupling in an optical fiber Bragg grating (FBG) is proposed and demonstrated. The FBG’s cladding is micro-machined into micro-curvities aided by femtosecond laser, and coated with TbDyFe, magnetic sensing element. Number of micro-curvities and laser energy under a laser beam were optimized during FBG micromachining and dramatically improved sensor performance. Six-micro-groove sensor is four times more sensitive as compared to non-micro-grooved standard FBG sample. The effect of 18 mW laser pulse power impacted magnetic sensitivity of magnitude 0.6 pm/mT as compared to 0.14 pm/mT on non-microstructured standard FBG sensor. The depth of the deposited magnetostrictive film was measured as ~5 μm.

Optical coherence tomography (OCT) with advantages of high resolution and high sensitivity is an emerging optical imaging technology that performs cross-sectional tomographic imaging of microstructure in biological system. In spite of the improvement of the longitudinal resolution by using low coherence light source, the dispersion effect aggravates with the increase of spectral bandwidth, which result in serious image blur and loss of image features. We demonstrate a double-path rapid scanning optical delay line (D-RSOD) structure in reference arm that produce the additional phase delay and group delay independent in OCT. The phase delay determined by grating defocus offset (GDO) of D-RSOD is controllable and the system dispersion is compensated by accurate adjustment of GDO in experiment. The full width at half maximum (FWHM) of the interference peak was measured to be 23.2μm and 15.2μm respectively before and after compensation. The experimental results indicate that the interference signal envelops shrink and the tomographic image clarify after dispersion compensation, D-RSOD is an effective means of dispersion compensation in OCT as well.

This paper demonstrates the duality property of medium tensor under optical effect, deduces dual normal vector equation under optical effect based on the unified normal vector formula, and proves the redundancy of normal vector equation. Besides, this paper deduces non redundant Eigen equation based on property of transmission tensor, and analyzes Eigen vibration vector and refractive index. The research has a certain guiding significance for the design of the measuring device based on optical effect.

The measurement of sky background infrared radiation is one of the important means to obtain background photoelectric characteristics. For general atmospheric measurement software, regional differences are ignored and particular area sky background optical properties can’t be reflected. A measurement method of sky background infrared radiation characteristic based on infrared image inversion is proposed to solve all these problems mentioned above. Firstly, radiation responsiveness is determined by calibrating the infrared measurement equipment. Secondly, using the equipment, sky background image, atmospheric transmittance and atmospheric path radiation data are obtained. Finally, according to the radiation responsiveness of the measuring equipment and atmospheric transmittance data, the sky background infrared radiation is inversed. The experimental result shows that the sky background luminance data of the proposed method and LOWTRAN7 are in good agreement, meeting the needs of practical application.

With the method of ultraviolet absorption spectrum, the exact absorption cross-section with the light source of the low-pressure mercury lamp was determined, during which the optimum wavelength for mercury concentrations inversion was 253.69 nm, the highest detection limit was 0.177 μg/cm³, and the lowest detection limit was 0.034 μg/cm³. Furthermore, based on the differential optical absorption spectroscopy(DOAS), the relationship between the integral parameters (IP) and the concentration as well as the signal-noise ration (SNR) under the conditions of gas flow was determined and the lowest detection limit was figured out to be 0.03524 μg/cm³, providing a method of DOAS to de-noise through the comparison between the mercury concentration values produced by DOAS and that produced by the wavelet de-noising method (db5). It turned out that the differential optical absorption spectroscopy had a strong anti-interference ability, while the wavelet de-noising method was not suitable for measuring the trace concentration change.

The influence of ambient temperature is a big challenge to robust infrared face recognition. This paper proposes a new ambient temperature normalization algorithm to improve the performance of infrared face recognition under variable ambient temperatures. Based on statistical regression theory, a second order polynomial model is learned to describe the ambient temperature’s impact on infrared face image. Then, infrared image was normalized to reference ambient temperature by the second order polynomial model. Finally, this normalization method is applied to infrared face recognition to verify its efficiency. The experiments demonstrate that the proposed temperature normalization method is feasible and can significantly improve the robustness of infrared face recognition.

Resonant Cavity Enhanced Photodetectors (RCE-PDs) are a possible solution to overcome the trade-off between bandwidth and quantum efficiency in the conventional photodetectors. In RCE-PDs, thin absorption layer gives rise to a large bandwidth, while the multiple passes of light in the absorption layer due to the resonant cavity increases the quantum efficiency. In this paper, an extended calibrated circuit model for RCE-PIN-PD is presented. This model includes the effects of the biasing of the photodetector resulting in the feasibility of a complete circuit simulation of the entire photoreceiver circuit. The effects of the biasing over the performance of RCE-PIN-PDs have been studied for different loads and different thicknesses of the absorption layer of the photodetector. Based on the studies of different parameters for design and materials, optimization has been performed for the RCE-PINPDs. With this optimization, the optimal values of the thickness of the absorption layer to produce the highest bandwidth of the photodetector are obtained for different biasing values. These optimizations are performed for different areas of the photodetector and also for different load resistors, and they result in a significant improvement in the performance of this type of photodetector.

A series of amorphous-Si/silicon oxynitride multilayer were deposited on the ITO (40Ω/cm) glass substrates in a very high frequency plasma enhanced chemical vapor deposition (VHF-PECVD) system. We prepared 8-period a-Si/ SiO_xN_y multilayer with thickness of 4 nm both for the amorphous Si and SiO_xN_y sublayers. The EL diodes can operate at room temperature and the turn-on voltage is about 10V. We study the room-temperature electroluminescence from as deposited amorphous-Si/silicon oxynitride multilayer structure.

The Eu-doped SiOC films were prepared by magnetron sputtering technique at a low temperature of 250°C. The effects of the Eu₂O₃ deposited power and post-thermal annealing temperature on the PL characteristics of the Eu-doped SiOC films were investigated. It is found that the photoluminescence intensity could be enhanced by more than tenfold by increasing the Eu₂O₃ deposited power from 20W to 80W. Furthermore, very bright blue light emission can be clearly observed with the naked eye in a bright room for the Eu-doped SiOC films prepared at a Eu₂O₃ deposited power of 80 W. The improved PL intensity is attributed to the increasing number density of europium silicate clusters as a result of the increasing Eu₂O₃ deposited power as well as high annealing temperatures.

Publisher’s Note: This paper, originally published on 22 August 2015, was withdrawn on 19 November 2021 per author request.

In the visible light communication, the white LED bandwidth severely limits the transmission rate of information. This paper presents an analog pre-equalization technology to compensate for the bandwidth of white LED. The technology not only can debug according to the actual channel changing, but also avoid the high costs of using FPGA technology. The pre-equalization technology is implemented by an analog circuit of tapped-delay-line, in the circuit we select an appropriate delay line and a digital to analog converter. In our LED visible light communication system, we can achieve a bandwidth of 150MHz，which was proved theoretically in the paper.

BaTiO₃ film is deposited on single crystal MgO substrate with pulsed laser deposition, and its crystal structure and surface roughness are characterized by X-ray diffraction instrument and atomic force microscope. BaTiO₃ film crystal quality is analyzed under three different oxygen partial pressure and three different annealing temperatures. The result shows that when the oxygen partial pressure is 15Pa, crystal surface (001) and (002) diffraction peak of BaTiO₃ thin films have higher intensity. It indicated that the film has a good c-axis orientation. When the annealing temperature is 800°C, the intensity of diffraction peak is the maximum, and peak shape is sharper. BaTiO₃ crystal film is obtained with highly preferred orientation, and film density is improved. Thus the film has less surface roughness and good crystalline state.

Hyperspectral blood image has been utilized in biomedical field for a period of time. However, identifying and segmenting blood cells is still a tricky issue. Thus, this paper proposed a new method based on support vector machine (SVM) to solve this issue from hyperspectral images. Then post-processing of holes-filling and noise removing are performed on the segmented results to get completed cell. The experimental results proved the accuracy and accommodation for this new proposed method.

The performance of graphene based Schottky junction solar cell on silicon substrate is studied theoretically by TCAD Silvaco tools. We calculate the current-voltage curves and internal quantum efficiency of this device at different conditions using tow dimensional model. The results show that the power conversion efficiency of Schottky solar cell dependents on the work function of graphene and the physical properties of silicon such as thickness and doping concentration. At higher concentration of 1e17cm-3 for n-type silicon, the dark current got a sharp rise compared with lower doping concentration which implies a convert of electron emission mechanism. The biggest fill factor got at higher phos doping predicts a new direction for higher performance graphene Schottky solar cell design.

Taking metallic cantilever beam as the research subject, using fiber Bragg grating strain sensing array as the detecting means, a new method is studied to detect multi-crack damage of cantilever beam. First, the strain test method of fiber Bragg grating sensing array is studied. Damage of cantilever beam has been prefabricated by using the wire-cutting technology. When the cantilever beam is not damaged, the wavelengths of fiber Bragg grating are changed by adding the weight, then the changes of fiber Bragg grating wavelength are acquired, and the changes are taken as the initial data. When one crack is prefabricated on the cantilever beam, using the foregoing method, the wavelengths of fiber Bragg grating are changed by adding a weight. The changes of fiber Bragg grating wavelength are acquired. The first group of damage data is obtained. Accordingly, the second crack and the third crack are prefabricated in the cantilever beam. Using the foregoing method, the other two groups of damage data are acquired. So three groups of damage data are obtained, then comparing the three groups of damage data with the undamaged data, and the damage recognition of cantilever beam is realized. The experimental result indicates that fiber Bragg grating strain sensing array can exactly and sensitively detect damage information of cantilever beam. It is a new sensing method in damage recognition field.

The stereo vision technology by two or more cameras could recovery 3D information of the field of view. This technology can effectively help the autonomous navigation system of unmanned vehicle to judge the pavement conditions within the field of view, and to measure the obstacles on the road. In this paper, the stereo vision technology in measuring the avoidance of the autonomous vehicle is studied and the key techniques are analyzed and discussed. The system hardware of the system is built and the software is debugged, and finally the measurement effect is explained by the measured data. Experiments show that the 3D reconstruction, within the field of view, can be rebuilt by the stereo vision technology effectively, and provide the basis for pavement condition judgment. Compared with unmanned vehicle navigation radar used in measuring system, the stereo vision system has the advantages of low cost, distance and so on, it has a good application prospect.