This PDF file contains the front matter associated with SPIE Proceedings Volume 8559, including the Title Page, Copyright information, Table of Contents, and the Conference Committee listing

Hollow core photonic crystal fiber (HCPCF) employs a guiding mechanism fundamentally different from that in conventional index guiding fibers. In an HCPCF, periodic air channels in a glass matrix act as reflectors to confine light in an empty core. As a result, the interaction between light and glass can be very small. Therefore, HCPCF has been used in applications that require extremely low non-linearity, high breakdown threshold, and zero dispersion. However, their applications in optical sensing, especially in chemical and biological sensing, have only been extensively explored recently. Besides their well-recognized optical properties the hollow cores of the fibers can be easily filled with liquid or gas, providing an ideal sampling mechanism in sensors. Recently, we have demonstrated that by filling up a HCPCF with gas or liquid samples, it is possible to significantly increase the sensitivity of the sensors in either regular Raman or surface enhanced Raman scattering (SERS) applications. This is because the confinement of both light and sample inside the hollow core enables direct interaction between the propagating wave and the analyte. In this paper, we report our recent work on using HCPCF as a platform for Raman or SERS in the detection of low concentration greenhouse gas (ambient CO2), biomedically significant molecules (e.g., glucose), and bacteria. We have demonstrated that by filling up a HCPCF with gas or liquid samples, it is possible to significantly increase the sensitivity of the sensors in either regular Raman or SERS applications.

A new method for precisely measuring the optical phase retardation of wave-plates in the infrared spectral region is presented by using modulated-polarized visible light. An electro-optic modulator is used to accurately determine the zero point by the frequency-doubled signal of the Modulated-polarized light. A Babinet-Soleil compensator is employed to make the phase delay compensation. Based on this method, an instrument is set up to measure the retardations of the infrared wave-plates with visible region laser. Measurement results with high accuracy and sound repetition are obtained by simple calculation. Its measurement precision is less than and repetitive precision is within 0.3%.

The singular points of time-averaged power flow in electromagnetic fields can be qualitative parameters to understand the behavior of energy flow of electromagnetic systems. Rough relations between the power transmission efficiency or field enhancement and the behavior of the singular points are discussed. In this study, we investigate the relation between the singular points in power flow and other physical characteristics such as the field enhancement or power transmission efficiencies. By investigating the power flows near isolated or periodic slits and antennas, we hope to provide another view of understanding the physics in those structures.

Next-generation optical communication and optical computing imply an evolution from binary to multinary computing. Light multinary computing encodes data using pulses of light components in higher orders than binary and processes it using truth tables larger than Boolean ones. This results in lesser encoded data that can be processed at faster speeds. We use a general-purpose optical transistor as the building block to develop the main computing units for counting, distributing, storing, and logically operating the arithmetic addition of two bytes of base-10 data. Currently available optical switching technologies can be used to physically implement light multinary computing to achieve ultra-high speed communication and computing.

Digital holography allows fast, nondestructive, full-field 3D measurement of reflecting as well as transmitting objects. It is a well-established two-step method of digital recording and numerical reconstruction of the full complex field of wavefront. It has found applications in diverse fields, such as micro-optics and MEMS metrology, cell imaging and particle characterization. However, for quantitative phase measurement there is 2π by phase ambiguities that limit measurements of optical path lengths to the wavelength of the illumination light. For continuous profiles, phase unwrapping is used to overcome the phase jumps. One approach is to use a synthetic wavelength using two lasers with different wavelengths. This synthetic wavelength would depend on the wavelengths of the two sources and thus can be tuned by selecting appropriate sources. In this paper, this concept is integrated into the compact digital holoscope which provides the system with the capability of measuring over a range of step heights from the nanometer to the micrometer realm. Applications of the system for reflecting geometries is discussed.

Hybrid WDM/TDM-PON as a key solution is a smooth evolution of the passive optical network to Next-Generation Passive Optical Networks (NG-PON). In order to combine the capacity of metro and access networks, it is desirable to propose the Long-Reach (LR) PON, and the propagation delay is proved to be the obstacle during the upstream resource allocation, so we propose an efficient DWPBA for the Long-Reach hybrid WDM/TDM-PON by separating the data messages and REPORT messages under multi-thread scheduling, which achieve high channel utilization and low packet delay when fiber length increased to 100 km.

A new holography display technology based on a phase-only spatial light modulator (SLM) is proposed. The normal use of laser diode (LD) light source led to the inevitable speckle noise introduced by the coherence of the laser beam. Algorithms and special diffractive optical elements have been proposed to reduce the speckle noise. In this paper, a selected light-emitted diode (LED) light source was used in the holographic display system to replace the LD light source. The temporal coherence and spatial coherence of the LED were studied. Though the temporal coherence of LED is short, the spatial coherence of the light field can be improved by optimizing the optical paths such as decreasing the emitting area of the light source and so on. A high-power LED with a narrow band-width was selected. An algorithm to generate computer-generated hologram for the SLM was proposed. The phase-only holograms for the display were computed using the coherent light algorithm. Then the phase holograms were uploaded to the SLM. LED was used as the light source to illuminate the SLM uniformly, and the reconstructions can be observed by naked eye. It is demonstrated that LED is an acceptable light source for holographic display. The reconstruction results showed that the speckle noise and multiple reflections were eliminated when LED was used as the light source.

Starting with the numerical calculation of the Fourier spectrum of the orthogonal phase-coded beam, a fundamental study on hybrid phase-coding and spatial multiplexing shows that there will be a complex and serious fluctuation in both intensity and phase distribution in the reference beam if a Fourier transform configuration is used for setting up the reference beam. In order to maintain phase-only modulation and orthogonality in the reference beam pattern, we suggest that the phase modulator should be imaged to the recording plane.

We propose a digital hologram generation method from diffracted intensity images based on the transport of intensity equation. In this paper we do experiment to verify the proposed method with coherent illumination with simple experiment setup using the intensity images capture process. The experiment results show that our proposed method has advantages compared to both the conventional holography with interferometry and the hologram generation based on multiple intensity images.

Multiple holographic gratings were recorded by 405nm laser in the same location of spirooxazine doped polymer films using peristrophic multiplexing techniques. Diffraction efficiency of each grating was controlled almost uniform by adjusting recording time. It was found that the growth rate of the holographic grating recorded later was lower than that of the earlier one, resulting from the decreased population of spirooxazine molecules. A kinetics description for the overlapped isomerization gratings agrees well with experimental results. Due to the thermal stability of the isomerization grating, multiple interference fringes in the photochromic film were reserved and observed by Confocal Laser Scanning Microscope.

Opto-electronic hybrid correlator can realize the combination of electronic flexibility and high speed of optical computing, so it has widely potential applications in high speed optical information processing system, especially recognition and tracking system. But the opto-electronic conversion speed and the positioning accuracy of correlation peak constrains the performance of this system. This paper first proposes an idea that PSD(Position Sensitive Device) can be applied in optical correlation peak detection instead of traditional CMOS/CCD sensor. It is displayed by theoretical analysis that this system can attain a correlation calculation speed of 20,000 frames per second, which indicates that the system can satisfy high speed demands of target recognition and tracking. Through optimal design of Fourier lens, the size, shape and intensity of the correlation peak spot have been optimized to satisfy the positioning accuracy requirement of PSD. The property of PSD can lead to nonlinear displacement error of the correlation peak and this paper use a linear line to fit the experimental outcome. Besides, this paper introduce the definition positioning accuracy, which is defined the maximum deviation apart from fitting linear outcome. The positioning accuracy of the novel opto-electronic hybrid correlator is calculated approximate 10 pixels (0.04mm), which is small enough to satisfy the demand of recognizing and tracking a target. In conclusion, a high speed and high accuracy recognition and tracking system has been realized based on the opto-electronic hybrid correlator.

Supramolecular azopolymers were prepared through strong hydrogen bonding interaction between pyridine moiety of poly (4-vinylpyridine) (P4VP) and phenol moiety of 4-nitro- 4’-hydroxyazobenzene (AzoOH). A multilayered composite film with supramolecular azopolymers as a recording layer and polyvinyl alcohol (PVA) as a spacing layer was prepared through alternately stacking. Under two-photon excitation, azobenzene chromophore can be orientated perpendicularly to the polarization direction of the writing beam via trans-cis-trans photoisomerization, yielding optical birefringence. Polarization-multiplexed and multilayered optical data storage were demonstrated by encoding two letters in the same region of each of the two layers based on the property.

The conception of construction of the family of the offered optoelectronic photocurrent reconfigurable (OPR) universal or multifunctional logic devices (ULD) consists in the use of a current mirrors realized on 1.5μm, 0.35μm, 65nm technology CMOS transistors. Presence of 44 transistors, 1÷5 photo-detectors makes the offered circuits quite compact and allows their integration in 1D and 2D arrays. The simulation results of the OPR ULD on the 1.5μm, 0.35μm, 65nm technology CMOS transistors showed that the level of logical unit can change from 20nA, 50nA, 500nA 1μA to 10μA for low-power consumption variants and from 20-500nA to 1-10μA for high-speed variants. The base cell of the OPR ULD consist of a small amount of photo diodes, transistors and LED have low power consumption <1μW-5mW. Modeling of such cells in OrCad is made. It is confirmed that all set of possible functions will be realized such OPR ULD by a simple photo-tuning with 1012 op/s.

A construction of the optoelectronic system with binary power spectrum is presented for target recognition. In the beginning, the minimum average correlation energy method is used to yield the reference function. Then, the multi-level quantized reference function is implemented at the input plane of the liquid crystal spatial light modulator in the joint transform correlator . Numerical result is presented.

Recognition of low-light level target is attracting more and more concern in modern military areas. However, for the reason of low contrast, low signal-to-noise ratio and inadequacy information of low-light level target etc, the goal to detect and recognize the target would not be realized by using photoelectric joint transform correlator. By median filtering and edge detection with lifting wavelet transform for low-light level target in this paper, the interference of background noise is reduced and useful information of target and template is enhanced at the same time. Experimental results show that the brightness and contrast of correlation peaks are both improved obviously after processing the joint image, which proves the method is very effective in target recognition field by using photoelectric hybrid joint transform correlator.

The image pattern recognition can accurately identify and locate the target, but image pattern recognition is unable to accurately recognize the distorted targets (the targets rotated in plane or scale changed), which has restricted the development of the image pattern recognition. In order to solve the problem of inaccurate recognition for distorted target in cluttered background among the image pattern recognition, the distorted target images and the training images are edge extracted by canny operator. The Optimum Trade-off Maximum Average Correlation Height (OT-MACH) filter is synthesized with the edge extracted training images. The low frequency information of the distorted target images and the filter is enhanced. Then the edge extracted distorted target image is filtered by the OT-MACH filter. Thereby, the distortion tolerance of the OT-MACH filter is expanded. It can respond higher correlation peaks and have higher distortion tolerance to recognize various types of distorted targets in cluttered background. By this method, which the space edge extraction combines with frequency domain filtering, the scale distortion tolerance is 0.72~1.42 times; the rotation distortion tolerance can reach up to 70 degrees. In order to prove the feasibility of this method, a lot of computer simulation experiments have been done with the canny operator and the OT-MACH filter.

Gain and phase dynamic characteristics in the compressive, unstrained and tensile strained InGaAs-InGaAsP quantum well (QW) semiconductor optical amplifiers (SOAs) are theoretically investigated via a detailed model. Based on the calculation of energy band structure, the effects of compressive and tensile strain on the differential gain and the derivative of refractive index change are investigated. It is demonstrated that the compressive strained QW SOA shows the fastest gain recovery rate and the largest phase change. That is because the SOA has the characteristics of the largest differential gain and the smallest derivative of refractive index change. In addition, the ultrafast recovery process due to the carrier heating effect can be enhanced significantly in the tensile strained QW SOA.

GRIN medium with a lateral sech refractive index variation, can make normal-incident light beam gradually curve to the medium with a larger refractive index, and periodically converge the light beam to a point smoothly and continuously. This property of GRIN medium can be used as a coupl er to realize a mode spot size conversion. This paper mainly discussed the transmission property of Gaussian light beam in a sech GRIN medium by numerical simulation. SOI waveguide is widely used in the photonic integrated circuit. To achieve a higher coupling efficiency between single mode optical fiber and single mode SOI slab waveguide, which suffer a great light beam coupling loss for the mismatch of the spot size. The GRIN medium coupling structures are designed as a coupler, with symmetric refractive index distribution and asymmetric refractive index distribution. The insertion loss calculated in theory are 0.71dB and 1.35dB respectively, which has a significant improvement in coupling loss, compared with the 30dB coupling loss caused by direct butt -joint transmission.

Target tracking has a wide application in varieties of domains and has a rapid development at home and abroad, so the research on target tracking is more valuable in recent years. In this paper hybrid optoelectronic joint transform correlator (HOJTC) is implemented for tracking the target, which is considered as one of the most effective methods. But in practical application, the low contrast character of the target and the moving distortion problems between the target and the template may cause the phenomenon of low recognition ratio of HOJTC. In order to solve this problem, a kind of wavelet-based threshold segmentation method is applied to increase the contrast. Through this algorithm the histogram of the image is firstly decomposed into wavelet coefficients at every scale with wavelet basis function Sym4. And then according to segmentation norm and wavelet coefficients, the thresholds can be chosen from the reconstructed histogram. Finally use these thresholds to segment the image into ideal areas. In addition, for the moving distortion problem, taking temporal state of the target as the template can realize the template update. To prove this method, many tracking experiments of low contrast targets have been performed with optical correlation method. As an example a low contrast target “tank” (the gray contrast is less than 2%) is presented. The tracking result shows that the brightness of the correlation peaks is enhanced and the target recognition ratio is increased. The conclusion can be drawn that applying this algorithm in optical correlation method can implement the low contrast target tracking successfully and this algorithm provides an available solution to low contrast target tracking.

A new optical isolator mode which is based on the theory of SPP has been designed. A dielectric waveguide and a SPP waveguide are formulated. And there is a gap in the middle of the core in the dielectric waveguide. Low refractive index material is filled into the gap and the total reflection is satisfied at the interface of the two materials. Magneto-optic material is contained in the two waveguides and the two waveguides are stacked together. For the phase matching of the two waveguides and the total reflection at the gap, the light couples from the dielectric waveguides into the SPP waveguides. With the help of the SPP, the light passes the gap successfully and couples into the dielectric waveguide again. However, there is a different situation at the reverse direction. For the effect of the magnetic field, the permittivity of magneto-optic material has been changed and this caused the phase mismatching of the two waveguides. So effective coupling is not able to finish between the two waveguides. With the total reflection at the gap of the core, the light cannot traverse the mode, and the aim that reflected light should be isolated is achieved. The insertion loss value is 1.72dB when the light traverses through the optical isolator in forward direction. In the reverse direction, the isolation value is 34.14dB. And this result is better than the common magneto-optical isolator.

All-optical programmable logic arrays (PLAs) based on canonical logic units (CLUs), i.e. minterms and maxterms, are presented. We experimentally demonstrated the full set of two-input and three-input minterms as well as maxterms using the cross-gain modulation in semiconductor optical amplifiers (SOAs). Maxterms can be easily obtained based on minterms. The reconfigurability and scalability of the system are largely enhanced compared to our previous work. Correct and clear temporal waveforms are achieved for all the canonical logic units. The measured extinction ratios of two-input and three-input CLUs are ~ 15 dB and ~ 11 dB, respectively. Four important logic functions, including multiplier, multiplexer, demultiplexer and decoder, are presented as examples to show that the canonical logic units-based programmable logic array (CLUs-PLA) can be reconfigured to perform different logic functions.