This PDF file contains the front matter associated with SPIE Proceedings Volume 8054, including the Title Page, Copyright information, Table of Contents, and the Conference Committee listing.

Simulation results of the performance of a semiconductor resonant cavity linear interferometric intensity modulator are presented. Starting from the rate equations of an injection locked semiconductor laser, the phase response and stable locking range of the injection locked semiconductor laser were obtained. Within the stable locking range without any approximation on the injection power level, effects of the alpha parameter or linewidth enhancement factor of the injection locked semiconductor slave laser, injection ratio, refractive index, and the residual amplitude modulation on the spur-free dynamic range (SFDR) of the modulator are studied.

Fabry-Perot filter arrays have been fabricated comprised of six million individual filters using standard semiconductor processing techniques. The current 3000x2000 array consists of 5x5 sub-arrays in which each of the nine micron wide Fabry-Perot filters in the sub-array has a different color response. The 5x5 sub-array is replicated to create a 600x400 matrix of 5x5 micro Fabry-Perot filter sub-arrays. This Fabry-Perot matrix has been integrated with a commercially available panchromatic 6 Megapixel CCD focal plane array to create a 25 color hyperspectral camera with 600x400 imaging pixels. Near-UV, visible and NIR filter arrays have been fabricated. The semiconductor processing technique permits filter arrays of general filter size, shape, configuration and distribution to be implemented with ease.

We demonstrate independent modulation of four optical comb lines at rates of up to 3.125 GHz by injection-locking a VCSEL to each of the comb lines. The comb-lines are separated by 6.25 GHz, as determined by the channel separation of the fiberized, matched-pair of demultiplexer and multiplexer. The currents to the VCSELs are modulated at frequencies between 0.78125 and 3.125 GHz and the resulting optical waveforms are measured using a fast photodiode and a high-bandwidth, real-time oscilloscope. The electronic waveforms have envelopes with periodicities corresponding to the current-modulation frequencies, and the pulse-shapes within one period of the envelope vary. The measurements prove that dynamic reconfiguration of the optical pulse-shape has been achieved at rates approaching the repetition rate of the comb source.

Data are presented demonstrating a new lithographic vertical-cavity surface-emitting laser (VCSEL) technology, which produces simultaneous mode- and current-confinement only by lithography and epitaxial crystal growth. The devices are grown by solid source molecular beam epitaxy, and have lithographically defined sizes that vary from 3 μm to 20 μm. The lithographic process allows the devices to have high uniformity throughout the wafer and scalability to very small size. The 3 μm device shows a threshold current of 310 μA, the slope efficiency of 0.81 W/A, and the maximum output power of more than 5 mW. The 3 μm device also shows single-mode single-polarization operation without the use of surface grating, and has over 25 dB side-mode-suppression-ratio up to 1 mW of output power. The devices have low thermal resistance due to the elimination of oxide aperture. High reliability is achieved by removal of internal strain caused by the oxide, stress test shows no degradation for the 3 μm device operating at very high injection current level of 142 kA/cm² for 1000 hours, while at this dive level commercial VCSELs fail rapidly. The lithographic VCSEL technology can lead to manufacture of reliable small size laser diode, which will have application in large area 2-D arrays and low power sensors.

A CW injection locked Coupled Opto-Electronic Oscillator (COEO) is presented with a 10.24 GHz spaced optical frequency comb output as well as a low noise RF output. A modified Pound-Drever-Hall scheme is employed to ensure long-term stability of the injection lock, feeding back into the cavity length to compensate for cavity resonance drifts relative to the injection seed frequency. Error signal comparison to an actively mode-locked injection locked laser is presented. High optical signal-to-noise ratio of ~35 dB is demonstrated with >20 comblines of useable bandwidth. The optical linewidth, in agreement with injection locking theory, reduces to that of the injection seed frequency, <5 kHz. Low amplitude and absolute phase noise are presented from the optical output of the laser system. The integrated pulse-to-pulse energy fluctuation was found to be reduced by up to a factor of two due to optical injection. Additional decreases were shown for varying injection powers.

The optical properties of cascaded plasmon resonant metallic nanocomposites are investigated. Plasmon resonances and their related field distributions are numerically evaluated in two-dimensional arrays of spherical silver nanoparticles embedded in a dielectric host. The field distributions in structures with identical particle sizes indicate the presence of a largely dipolar particle response, with a small multipole resonance contribution at high frequency. However, in arrays consisting of particles with dissimilar sizes, an additional coupled mode appears in which the dipole moment in adjacent particles is found to be anti-parallel. For increasing size-dissimilarity a higher electric field enhancement is observed inside the small metal nanospheres, indicative of a cascaded field enhancement effect. This effect may be used to enhance the nonlinear optical response of an effective medium composed of particles with engineered size dispersion and particle placement.

An optical comb source based on a slab-coupled optical waveguide amplifier (SCOWA) is presented. The laser is harmonically mode-locked at 10.287 GHz repetition rate and stabilized to an intra-cavity Fabry-Pérot etalon via Pound- Drever-Hall locking. The Fabry-Pérot etalon serves as a reference for the optical frequency of the comb-lines and suppresses the fiber cavity modes to allow only a single longitudinal mode-set to oscillate, generating a frequency comb spaced by the repetition rate. The pulse-to-pulse timing jitter and energy fluctuations are < 2 fs and < 0.03%, respectively (integrated from 1Hz to 100 MHz). Fundamental to this result is the incorporation of the SCOW amplifier as the gain medium and the use of an ultra-low noise sapphire-loaded cavity oscillator to mode-lock the laser. The SCOWA has higher saturation power than commercially available gain media, permitting higher intra-cavity power as well as available power at the output, increasing the power of the photodetected RF tones which increases their signal-to-noise ratio. A high visibility optical frequency comb is observed spanning ~3 nm (at -10 dB), with optical SNR > 60 dB for a cavity with no dispersion compensation. Initial results of a dispersion compensated cavity are presented. A spectral width of ~7.6 nm (-10 dB) was obtained for this case and the pulses can be compressed to near the transform limit at ~930 fs.

This work discusses the development of a frequency chirped, low repetition rate, semiconductor based mode-locked laser having reduced noise over previous demonstrations. Specifically, we present a major upgrade on the 100 MHz harmonically mode-locked Theta (Θ) laser cavity design in the form of the introduction of an intra-cavity fiberized Fabry-Perot etalon. The initial demonstration of the Theta cavity design offered improved energy per pulse and a linearly chirped pulse output compared to conventional cavity designs. Nonetheless, it suffered from pulse-to-pulse timing and energy noise. The noisy operation arises from the harmonic nature of the laser. To mitigate this effect we have inserted a fiberized etalon within the laser cavity. The intra-cavity etalon stores and inter-mixes the pulses of the harmonically mode-locked laser, as well as enforces lasing on a single optical mode-set from the multiple interleaved sets supported by the mode-locked laser due to its harmonic nature. This leads to the generation of a stable optical frequency comb with 100 MHz spacing and the suppression of the RF super-mode noise spurs, which results in a reduction of the laser noise. Due to fiber length drift in both the fiberized laser cavity and the fiberized etalon, a long-term stabilization scheme is necessary. An intra-cavity Hansch - Couillaud scheme is employed. The laser outputs chirped pulses with 10 nm of bandwidth. This work provides an in depth analysis of both the development of the Theta cavity with the intra-cavity etalon and the performance of the developed laser system.

The IEEE Std 802.3ba-2010 for 40 Gb and 100 Gb Ethernet was released in July, 2010. This standard will continue to evolve over the next several years. Two of the challenging transmit/receive architectures contained in this standard are the 100GBASE-LR4 (<10 km range) and 100GBASE-ER4 (<40 km range). Although presently envisioned for 1310 nm optical wavelengths, both of these 4 lane, 25.78 GBaud formats may be adopted for the impending 850 nm short reach optical backplane market, whose range is below 150 m. Driven by major computer server companies, such as IBM, HP and Oracle, the 850 nm Active Optical Cable (AOC) market is presently undergoing an increase of serial rates up to 25 Gbaud to enhance backplane interconnectivity. With AOCs up to 16 channels, the potential for up to 400 Gbps backhaul composite data rates will soon be possible. We report a 25 Gbps photodiode with quantum efficiency ~ 0.6 at 850 nm. This InGaAs/InP device was optimized for high quantum efficiency at 850 nm. When pigtailed with multimode fiber and integrated with an application-specific RF amplifier, the resultant photoreceiver will provide multiple functionalities for these 100 Gb Ethernet markets.

Free-space optical links are ideal for short-range (1 km to 3 km) communications. An innovative new technique called Spatial Optical Encryption can be used to secure laser data communications. With this technique, data can be encoded and transmitted spatially through a single fiber, and then transmitted over a free-space optical link. Different sources of data could be simultaneously sent over the same fiber. This endeavor demonstrates the design and performance issues of such a transmitter and receiver using Spatial Optical Encryption over an environmental link of 100 meters.

An optical encryption technique based on polarization property of light is proposed. Many techniques using polarization beam splitters to encrypt the signal have been proposed earlier. They are based on splitting and interference of two light signals, namely message and noise. Only by placing suitable mirrors and a second beam splitter in a suitable position, the two signals are reconstructed at the output. In this paper we report the fiber optic version of a polarization based encryption technique that also has the potential to double the data carrying capacity of the fiber. Using polarization dependent couplers in the fiber optic cables, we are able to achieve encryption of the light signal. Theoretical analysis and simulated results are also presented.

Current high speed networks have reached a throughput capacity in practical implementation of up to OC-768. Current commercial of the shelf (COTS) hardware cannot meet the requirements for full data capture at these rates. In this paper, we first provide an analysis of capabilities of best available hardware. We then propose a method for non-standard configuration of hardware to provide for high speed data capture at 40 Gbps and beyond. This configuration will provide a suitable hardware back-end to enable transport, storage, and processing of the 40+ Gbps full duplex captured data to enable forensics without disposing of any potentially valuable information.

Much work to date has been done in the identification of physical layer optical network attacks. Our own work has indicated additional attacks against data integrity through various forms of optical coupling. In this paper, we present an analysis of coupling attacks on a fiber optic link. In addition we demonstrate on such form of a coupling attack using standard hardware and allowing injection of additional data onto the fiber. This method introduces minimal power losses that are well below most physical layer intrusion detection sensor thresholds.

Spatial domain multiplexing (SDM) utilizes co-propagation of exactly the same wavelength in optical fibers to increase the bandwidth by integer multiples. Input signals from multiple independent single mode pigtail laser sources are launched at different input angles into a single multimode carrier fiber. The SDM channels follow helical paths and traverse through the carrier fiber without interfering with each other. The optical energy from the different sources is spatially distributed and takes the form of concentric circular donut shaped rings, where each ring corresponds to an independent laser source. At the output end of the fiber these donut shaped independent channels can be separated either with the help of bulk optics or integrated concentric optical detectors. This presents the experimental setup and results for a four channel SDM system. The attenuation and bit error rate for individual channels of such a system is also presented.

We report the fabrication of a saturable absorber made of a novel polymer SU8 doped with Single Wall Carbon Nanotubes (SWCNTs). A passive mode-locked ring cavity fiber laser was built with a 100 μm thick SU8/SWCNT film inserted between two FC/APC connectors. Self-starting passively mode-locked lasing operation was observed at 1572.04 nm, with a FWHM of 3.26 nm. The autocorrelation trace was 1.536 ps corresponding to a pulse-width of 871 fs. The time-bandwidth product was 0.344, which is close enough to transform-limited sech squared pulses. The repetition rate was 21.27 MHz, and a maximum average output power of 1 mW was also measured.

We propose and numerically demonstrate impairment compensation via digital backward propagation (DBP) for fiber transmission with distributed Raman amplification. In contrast to EDFA-based systems, signal power evolution in the distributed amplified system has to be obtained prior to DBP by solving the differential equations for Raman amplification. The optimum launching power of an unrepeatered Raman link is significantly increased by nonlinearity compensation.

Up to now the knowledge is limited as far as adverse effects are concerned which are the result of temporary blinding from high brightness optical products, like laser pointers, but it is mandatory to be aware of the degree and influence on various visual functions of persons performing challenging activities, especially under mesopic or even scotopic conditions. Therefore various test scenarios have been designed in the laboratory and bright optical radiation from highbrightness LEDs and laser products applied as light sources in order to simulate the temporary blinding of pilots during a night-flight, especially during landing. As an important realistic test object the primary flight display (PFD) of a commercial aircraft has been integrated in the respective test set-up and various alignments on the PFD could be adjusted in order to measure the time duration which is needed to regain the ability to read the respective data on the PFD after an exposure. The pilot's flight deck lighting situation from a full flight simulator A 320 has been incorporated in the test scenarios. The level of exposure of the subjects has been limited well below the maximum permissible exposure (MPE) and the exposure duration was chosen up to a maximum of 10 s. A total of 28 subjects have been included in various tests. As a critical value especially the visual search time (VST) was determined. A significant increase of VST between 2.5 s and 8 s after foveal irradiation has been determined in a specially designed test with a primary flight display (PFD) whereas an increase of 9.1 s for peripheral and 9.9 s for frontal irradiation resulted in an exercise (flight maneuver) with a Microsoft flight-simulator. Various pupil diameters and aversion responses of the subjects during the irradiation might be responsible for the relatively large spread of data, but on the other hand a simple mean value would not comply with the spectrum of functional relationships and possible individual inherent physiological and voluntary active reactions of the irradiated persons, respectively.