We demonstrate a flexible optical waveguide film with integrated Vertical-cavity surface-emitting laser (VCSEL) and positive-intrinsic-negative (PIN) photodiode arrays for fully embedded board level optical interconnects. The optical waveguide circuits with 45° micro-mirror couplers are fabricated on a thin flexible polymeric substrate by soft molding. 45° micro-mirrors on waveguide array for fully embedded board level optical interconnections are investigated both theoretically and experimentally. Smooth mirror surface fabrication is demonstrated by using microtome blade. Thin film VCSEL arrays and PIN photodiode arrays are directly integrated on to the waveguide film. Measured propagation loss of the waveguide was 0.3dB/cm at 850nm.

The advantages of optical interconnections, like low latency and large bandwidth, are currently becoming more important for on-board or multi-board systems. Clock distribution and data transfer with high channel density and high frequency over areas in order of several centimeters up to a few meters are of interest, e.g., in multi-processor systems. As an approach to solve the challenges of interconnections and fanning we investigate planar integrated free-space optical systems (PIFSO). In the "High-speed Opto-eLectronic Memory System" project (short: HOLMS), supported by the European Commission, a multi-processor system with optical processor memory interconnection is being demonstrated. The system combines different optics technologies. The PIFSO technology is used as the interface between opto-electronic components and optical fibers and/or PCB-embedded waveguides. The tasks of this interface are to realize the pitch transfer, e.g. from the waveguide array to the opto-electronic device array, fan-in and fan-out. To realize the different aspects of these tasks, suitable micro-optical imaging techniques and fan-out approaches are considered. To handle the large numerical aperture of the optical multimode field emerging from the VCSEL-diodes and the waveguides (up to around 0.2), the concept of pupil division is being investigated for the fan-out operation. Practical aspects such as footprint and tolerances are also considered. The feasibility of implementation of the PIFSO interconnect will be shown by means of simulations and experimental demonstration.

A novel, truly CMOS compatible, waveguide coupled, high-speed photodiode for on-chip optical clock distribution is designed using analytical calculations, electro-optical simulations, and experimental analysis. Experiment and simulation results from test devices are presented and analyzed.

A specific case of a multi-phonon non-collinear light scattering in optically uniaxial media is presented. Compared to our previous studies, an innovation lies in the fact that now we consider passing just the quartet of incident light beams through a single crystal that is perturbed by the triplet of coherent acoustic waves. The exact and closed analytical model for describing this strongly nonlinear phenomenon is developed. In fact, specially designed regime of a four-order light scattering whit direct coupling of all the light modes, when transitions of four input light beams into four output light modes are allowed and electronically controlled, is examined. The feasibility of applying such an effect to an all-optical computing and performing an all-optical adder is analyzed.

Wavelength-selective switching is generally considered to be an essential element for building agile “all optical” mesh telecommunications networks. This paper will provide an overview of the various node architectures suitable for implementing such networks. It will also provide an overview of the various technologies, that have been developed for such networks, including integrated optical waveguide circuits and free-space optical devices. While these technologies were largely developed for telecommunications applications, they may also applicable for computer networks.

Spatial dragging of optical solitons is an asymmetric interaction in which a weak signal soliton propagating at a tilted angle can drag an initially overlapping strong pump soliton with orthogonal polarization to the side, thus missing a spatial aperture at the output. A novel ultrafast all-optical wavelength converter based on (3+1)-D soliton dragging interaction between frequency shifted solitons is demonstrated in this paper using numerical simulations. This device is not rate limited by carrier life time as previously demonstrated wavelength converters and potentially can reach a bit rate of 2TB/sec. The proposed wavelength converter can be used in future multi-wavelength soliton communication network or multi-wavelength optical logic based computing systems.

Emergency alarm systems, for example, that switch off critical processes in process plant, are vulnerable to deliberate or accidental sabotage through coupling of electromagnetic pulses (EMP) to wires and/or from sparks due to broken wires. A proposed system significantly reduces vulnerability by using a fast all-optical latch in conjunction with an optical sensor and optical fibers. Sparks cannot be created on breaking an optical beam and electromagnetic field transients have negligible effect on optical signals. The optical latch uses optical semiconductor amplifiers (SOAs) configured to form a flip-flop. The flip-flop latches after the occurrence of an intrusion that may be as short as a few nanoseconds, much faster than most environmental changes occur. Detection of an emergency or any break in connections causes the light to drop, triggering the alarm. Computer simulation shows that the all-optical latch is fast and effective.

Resolution enhancement in video sequences can involve a variety of enhancement techniques including deinterlacing, de-blurring, motion compensation, super-resolution and more. Depending on the video artifacts, techniques are chosen and applied to each frame in the video. The selected technique(s) is/are then applied to each complete video frame. This paper suggests using resolution improvement techniques, not on the complete frame, but only on specific moving vehicles within the frame. Using improved resolution only on the vehicles being tracked offers the possibility for improved local vehicle identification and enhancement to the near real-time vehicle tracking approaches. Additionally, the approach can save the computational cost associated with complete image frame enhancement. The paper develops a spatial-temporal deinterlaced resolution-ratio enhanced approach to a vehicle being tracked. For deinterlacing, this paper uses a variant of a recent new spatial-temporal technique which uses directional interpolation and motion compensation. The technique uses intra-field spatial and inter-field temporal interpolation. The suggested algorithm is demonstrated on a few video sequences and shows promise for near real-time application. The final processing result integrates targets through feature tracking creating the psychophysical "popout" effect with a higher target-to-background resolution ratio.

Today’s sensor networks provide a wide variety of application domain for high-speed pattern classification systems. Such high-speed systems can be achieved by the use of optical implementation of specialized POF correlator. In this research we discuss the modeling and simulation of the phase only filter (POF) in the task of pattern classification of multi-dimensional data.

The problem of automatic target recognition (ATR) and image classification have been active research fields in image processing. In this research, we explore ATR techniques such as object pre-processing, detection, tracking and classification for sequence of infrared (IR) images. The detection and tracking of IR images is performed using Bayesian probabilistic technique. The tracked part of the object frame is then processed to discard the background to obtain just the segmented object. The segmented dataset is then rendered shift invariant by first calculating the mean of the object and then moving the mean to center of the frame. We divide each frame into blocks and obtain statistical features such as mean, variance, minimum and maximum intensity in each block for subsequent classification. We visually divide entire IR dataset into 8 classes for supervised training using a K-nearest neighbor classifier. We classify the test IR dataset into 8 different classes successfully.

In laser beam position determination, various shapes of markers may be used to identify different beams. When matched filtering is used for identifying the markers, one is faced with the challenge of determining the appropriate filter to use in the presence of distortions and marker size variability. If the incorrect filter is used, it will result in significant position uncertainty. Thus in the very first step of position detection one has to come up with an automated process to select the right template to use. The automated template identification method proposed here is based on a two-step approach. In the first step an approximate type of the object is determined. Then the filter is chosen based on the best size of the specific type. After the appropriate filter is chosen, the correlation peak position is used to identify the beam position. Real world examples of the application of this technique from the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory are presented.

Automatic Target Tracking continuous to be an issue of major interest in the defense industry. However, evaluation of scenes and quantification of algorithm performance on different scenes continuous to be a challenging task. In this research we have developed a platform, or test bed, to test and compare the performance of various algorithms. Using this platform, different algorithms can be compared. Fifty unclassified scenes of different complexity provided by the Army Research Office are analyzed using this platform and phase only filter (POF) combined with two different functions defining the Region Of Interest (ROI). The ROI functions significantly speed up the search process.

This paper presents an overview of three recently developed scene-based nonuniformity correction techniques, namely, the algebraic scene-based algorithm (ASBA), the extended radiometrically accurate scene-based algorithm (RASBA) and the generalized algebraic scene-based algorithm (GASBA). The ASBA uses pairs of image frames that exhibit one-dimension sub-pixel motion to algebraically extract estimates of bias nonuniformity. The RASBA incorporates arbitrary sub- and super-pixel two-dimensional motion in conjunction with limited perimeter-only absolute calibration to obtain radiometrically accurate estimates of the bias nonuniformity. The RASBA provides the advantage of being able to maintain radiometry in the interior photodetectors without interrupting their operation. The GASBA is a generalized non-radiometric form of the algorithm that uses image pairs with arbitrary two-dimensional motion and encompasses both the ASBA and RASBA algorithms. This generalization is accomplished by initially guaranteeing bias uniformity in the perimeter detectors. This uniformity can be achieved by first applying the ASBA estimates. The generalized algorithm is then able to automatically maintain perimeter uniformity without the need for re-application of the ASBA. Thus, the GASBA is able to operate completely in a non-radiometric mode, alleviating the need for the perimeter calibration system if desired. The generalized algorithm is applied to real infrared imagery obtained from both cooled and uncooled infrared cameras. A hardware implementation of the proposed algorithm will also be discussed along with several ongoing commercial applications of the technology.

A numerical method for computing integer order Hankel transforms using a Fourier-Bessel expansion is presented. The method satisfies the discrete form of the Parseval theorem assuring energy conservation, this makes the formulation particularly useful for field propagation. Some relevant properties of the transformation matrix are discussed. Additionally, a numerical comparison with other typical methods is performed, the advantages and disadvantages of the method are discussed. To verify its accuracy to propagate an optical field, the method is used to obtain higher azimuthal order modes in an optical resonator using the iterative Fox & Li approach, resulting in a reduction of memory requirements and processing time, the results are compared to the traditional two-dimensional Fourier transform approach.

The design and development of binarized composite binary phase only filters for three-dimensional image identification is discussed in this paper. A composite binary phase only filter based algorithm is developed to detect an unknown image from the pre-constructed database. The angular position of the unknown image is found by a cross correlation technique. The formulation of composite filters reduces the number of correlation operations necessary for detection.

Two-photon scanning microscopes are imaging systems that are mainly featured by their unique depth-discrimination capacity when imaging three-dimensional objects. Along the past few years, our research group has done several attempts to improve their axial resolution by means of diffractive elements that properly shape the 3D point spread function. Our diffractive elements have been designed to work in the nonparaxial regime and are immune to a harmful effect, usually inherent to high-angle focusing systems, named as depolarization

Fast parallel processing of gray-scale images and exact hard-clip thresholding are two important functionalities necessary in optoelectronic implementations of structural processors. The parallel nature of processing stems from optical implementation of local operations with arrays of active smart pixels. We have demonstrated a morphological image processor composed of arrays of bistable optoelectronic transceivers which are connected in differential pairs and work as comparators. The use of differential pairs of optical thyristors fabricated in GaAs technology allows to realize a dual rail architecture for this photonic morphological image processor. The processor consists of a thresholding module and a binary morphological processing module. The thresholding module decomposes gray level images into series of binary slices. In the binary morphological processing module operations are performed within a neighborhood defined by a structuring element implemented as a diffractive fan-out element. In the prototype set-up we demonstrate median filtering, dilation and erosion operations performed for an image of 8x8 pixels and threshold decomposition of 6 gray level images. In principle all rank order as well as morphological filters can be optically calculated in the set-up. Additional functionality of the processor is achieved with use of the electronic layer with digital cellular processors. The electronic layer, designed as an array of simple digital processors, realizes a set of operations on binary images using 4 bit programmable weights. Simulation results for 0.8 µm CMOS technology are presented. We discuss the limitations of the photonic morphological image processing with respect to bandwidth, parallelism and architecture of the processor.

An algorithm for determining the position of the KDP back-reflection image was developed. It was compared to a centroid-based algorithm. While the algorithm based on centroiding exhibited a radial standard deviation of 9 pixels, the newly proposed algorithm based on classical matched filtering (CMF) and a Gaussian fit to correlation peak provided a radial standard deviation of less than 1 pixel. The speed of the peak detection was improved from an average of 5.5 seconds for Gaussian fit to 0.022 seconds by using a polynomial fit. The performance was enhanced even further by utilizing a composite amplitude modulated phase only filter; producing a radial standard deviation of 0.27 pixels. The proposed technique was evaluated on 900+ images with varying degrees of noise and image amplitude as well as real National Ignition Facility (NIF) images.

We describe some optical combinations of refractive and diffractive lenses to compensate for the inherent wavelength dispersion shown by interference and diffraction patterns under white-light point-source illumination. In a second phase, this achromatic behavior is also applied to the case of spatially incoherent polychromatic light, i.e., to totally incoherent illumination. Finally, the above results are extended to the correction of chromatic distortion associated with diffraction of femtosecond pulse light. Several experimental results are shown.

Intrinsic and extrinsic limitations on conventional top-emitting high-speed VCSEL modulation bandwidth are discussed. A new VCSEL structure has been designed with reduced constraints on modulation bandwidth. The structure simultaneously addresses the primary extrinsic factors that limit the VCSEL modulation bandwidth. The new bottom-emitting, flip-chipped VCSEL structure improves heat-sinking, current injection uniformity, and reduces parasitic capacitance. We estimate the ultimate bandwidth of this new structure to be as high as 40Gb/s.

We propose and implement simplifications to the optimum configuration of a twisted-nematic liquid-crystal display (TNLCD) operating as a phase modulator. As previously proposed, such an optimum configuration requires a generator of elliptic polarization, at the input, and a detector of elliptic polarization, at the output. Both the generator and the detector of elliptic polarization are formed by a quarter wave plate and a linear polarizer, appropriately arranged. As a first modification of the optimum phase configuration we removed the quarter-wave plate at the output of the TNLCD. The remaining components, two polarizers and a wave plate are arranged and oriented in such a way that the quality of phase modulation is very similar to that obtained with the arrange using two wave plates. This modification reduces complexity and cost of the mostly-phase setup arranged with the TNLCD. Our experimental implementation of the modified phase configuration employed a laser with a wavelength of 457 nm. As another modification of the setup, instead of a quarter-wave plate, optimized at 457 nm, we employed a half-wave plate optimized at 633 nm. The required elliptic state at the input of the TNLCD was generated by the appropriate arrangement of the linear polarizer and the wave plate.

High Speed Multi-Channel Fiber-Optic Transmitter (Tx) and Receiver (Rx) modules are needed for communication Applications. The fiber optic network should take advantage of the high speeds (10 Gbps/channel) and have the ability to connect multiple systems using fiber-optic network capable of working with 100’s of Gigabits of information. In addition, the network should provide redundant links between nodes so that in case one node goes out of service, the remainder of the network remains operational. In this paper we will present design, development and performance results for 1x12 Tx and Rx module operating at 10Gbps/channel. Each of the 1x12 modules is capable of providing 120 Gbps/Module operations for Military and Commercial Applications. Experimental results on 1x12 channel modules will include performance characteristics at 10 Gbps and will demonstrate high performance fiber-optical Tx and Rx Modules. We will also present architecture and simulation for a Fiber-Optic Network Card that has the capability to transmit and receive data, add and drop data at each node, and provide dual network redundancy. This network card includes Tx, Rx modules, serializer and de-serializer (SERDES) and a cross bar switch. This architecture can be used as a building block for high-speed local area network applications and also applicable to optical backplanes for distributed microprocessor communication.

Fiber sensors using Bragg Grating are emerging as one of the most prominent sensors to measure temperature and strain easily and accurately. In this paper we demonstrate a Fiber Bragg Sensor integrated to an angle facet laser to measure temperature and strain simultaneously.

Alignment of laser beams based on video images is a crucial task necessary to automate operation of the 192 beams at the National Ignition Facility (NIF). The final optics assembly (FOA) is the optical element that aligns the beam into the target chamber. This work presents an algorithm for determining the position of a corner cube alignment image in the final optics assembly. The improved algorithm was compared to the existing FOA algorithm on 900 noise-simulated images. While the existing FOA algorithm based on correlation with a synthetic template has a radial standard deviation of 1 pixel, the new algorithm based on classical matched filtering (CMF) and polynomial fit to the correlation peak improves the radial standard deviation performance to less than 0.3 pixels. In the new algorithm the templates are designed from real data stored during a year of actual operation.

In position detection using matched filtering one is faced with the challenge of determining the best position in the presence of distortions such as defocus and diffraction noise. This work evaluates the performance of simulated defocused images as the template against the real defocused beam. It was found that an amplitude modulated phase-only filter is better equipped to deal with real defocused images that suffer from diffraction noise effects resulting in a textured spot intensity pattern. It is shown that the there is a tradeoff of performance dependent upon the type and size of the defocused image. A novel automated system was developed that can automatically select the right template type and size. Results of this automation for real defocused images are presented.

The purpose of the automatic alignment algorithm at the National Ignition Facility (NIF) is to determine the position of a laser beam based on the position of beam features from video images. The position information obtained is used to command motors and attenuators to adjust the beam lines to the desired position, which facilitates the alignment of all 192 beams. One of the goals of the algorithm development effort is to ascertain the performance, reliability, and uncertainty of the position measurement. This paper describes a method of evaluating the performance of algorithms using Monte Carlo simulation. In particular we show the application of this technique to the LM1_LM3 algorithm, which determines the position of a series of two beam light sources. The performance of the algorithm was evaluated for an ensemble of over 900 simulated images with varying image intensities and noise counts, as well as varying diffraction noise amplitude and frequency. The performance of the algorithm on the image data set had a tolerance well beneath the 0.5-pixel system requirement.

The alignment of high energy laser beams for potential fusion experiments demand high precision and accuracy by the underlying positioning algorithms. This paper discusses the feasibility of employing on-line optimal position estimators in the form of model-based processors to achieve the desired results. Here we discuss the modeling, development, implementation and processing of model-based processors applied to both simulated and actual beam line data.

In order to meet the demand for miniaturization and excellent performances of antennas to send and receive the wireless signals, in this paper a novel Photonic Band Gap (PBG) structure of a two-dimensional square lattice array etched on one side of silicon wafer is proposed as the grounds of a microstrip patch antenna. An analysis of the performance of a patch antenna with a PBG ground has been carried out, then two rectangle MEMS microstrip antennas with a conventional and a PBG ground respectively, are designed, while the alternating direction implicit finite-difference time-domain (ADI-FDTD) is adopted to perform time simulations of Gaussian pulse propagation in the microstrip antennas, as a result of the versatile method, the frequency-dependent scattering parameters and input impedance could be derived. An important reduction of the surface waves in the PBG antenna has been observed in the simulations, which consequently leads to an improvement of the antenna efficiency and bandwidth. Subsequently, the MEMS PBG antenna is micromachined and measured, and the simulation characteristics are verified by the measured curves of the MEMS PBG antenna. The measured peak return loss of PBG patch antenna is -21dB at 5.36GHz, and the bandwidth of 8.5%, which is three times wider than that of the conventional patch, therefore the gain and the bandwidth are enhanced by means of PBG process.

In this paper, we summarized four novel microoptics gratings that have been made in Information Optics Lab in Shanghai Institute of Optics and Fine Mechanics. This first is the hexagonal grating for hexagonal array illumination based on the fractional Talbot effect, which is reported in Optics Letters 27, p.228 (2002). The second is the double layered computer generated hologram reported in Optics Letters 28, p.1513 (2003). This device could achieve dynamic optical functions by shifting or changing spatial light modulator in one layer for addressing the selected function in another layer. The third is the circular Dammann grating reported in Optics Letterrs 28, p.2174 (2003), which can generate the circular intensity at various orders in the far field. The fourth is the superresolution phase element reported in Optics Communications 228, p.271 (2003), which achieves the 0.8 compression ratio of the central diffraction spot compared with the usual Airy spot. This result is meaningful for confocal microscopy, and free-space laser communication, etc. In summary, these novel microoptical elements should be interesting for a variety of practical applications.

Ultra-high-speed Optical TDM (OTDM) signal transmission have a potential to provide fully wide bandwidth for long distance cost effective technology. OTDM transmission with 160Gbit/s, 640Gbit/s, 1Tbit/s over a single are studied and compared. However, the dispersion effect in OTDM system can impact the propagation for long distant transmission. In this paper, we simulation various dispersion compensation scheme to compare single mode fiber (SMF) and nonzero dispersion-shifted fiber (NZDSF) in the ultra-high speed data rate eye pattern improvement. This research is helpful for ultra-high speed computer networks investigations.

Array waveguide grating attract great attentions for wavelength division multiplexing fiber-optic communication system. In this paper, we design and analyze the integrated optical 64-channel arrayed waveguide grating (AWG) multiplexer/demultiplexer (mux/demux) with 0.4 nm (50GHz) channel spacing at 1.55μm based on silicon-on-insulator (SOI) waveguide. Assuming launching the fundamental mode as our initial mode propagating along these waveguides, the bandwidth level is -30dB, the uniformity of these devices is 0.5dB, and the maximum bend loss in 264 channel waveguides of the phased array of the AWG is 0.093dB in accordance of the simulation regulations. The crosstalk of the AWG mux/demux is less than -25dB. The insertion loss is controlled below 5dB.

In recently years, high-index-contrast semiconductor ring and disk resonators have attracted much attention. Nanofabrication techniques now allow the realization of semiconductor microcavity ring and disk resonators with evanescent wave coupling to submicron-width waveguides across submicron-width air gaps. In this paper, we use the finite-difference time-domain (FDTD) method to simulate the coupling efficiencies and resonant frequencies for optical microcavity ring and disk resonators devices. Studies of the transmission characteristics illustrate the transition from single-mode resonances to whispering-gallery-mode resonances as the waveguide width of the micro-ring approaching to a fulfilled micro-disk.

This paper reports recent work on gigabit Ethernet interconnection communication traffic analysis. We proposed and demonstrated the system concept of gigabit Ethernet communication. 1.25Gbps, 10Gpbs and 40Gpbs gigabit Ethernet interconnection networks are considered for computer communications. Various switching structures, such as crossbar, double crossbar (Dcrossbar), Modified Dilated Benes (MDB), General MDB (GMDB), Benes, Dilated Benes (Dbenes), Tree architecture, Simplified tree (Stree), Extended baseline network (Ebaseline) are analyzed for searching the optimal performance of gigabit Ethernet communication. The numerical results for computation information transferring can be applied to search a best strategy for gigabit Ethernet communication networks interconnections.

In this paper, we propose a new type of a polarization switch bases on KDP waveguide structure. The Czychroski’s method applied in de-ion water solution is introduced. We also show the experimental result of crystal growth by this method. The design principle of the TIR type switch is discussed to find the relationship between applied voltage (the electric field) and reduction of the refraction in a y-cut and x-propagation KDP substrate. We compare the insertion loss of KDP and other kinds of substrates to show the advantage of KDP crystal.

Although Optical wavelet transform has some advantages over discrete wavelet transform, but the mother wavelets to used are very few. That limits the signal processing ability of optical wavelet transform. Without scaling functions, the multiresolution analysis of a mother wavelet is not complete. In this paper, almost all the mother wavelets used in discrete wavelet transform are introduced into optical wavelet transform. Based on the analysis, we find whether the mother wavelets have analytical forms is not a necessary condition for implementing them in optical wavelet transform. Optical wavelet transform only needs to obtain the 2D approximations of wavelet functions. Then, with the cascade algorithm, the 1D approximations of scaling and wavelet functions are computed. By the scheme of 2D separable wavelet transform, the approximations of 2D scaling and wavelet functions are constructed. So mother wavelets frequently utilized in discrete wavelet transform are introduced into optical wavelet transform. With the increase of mother wavelet for selection, it is natural to classify optical wavelet transform into separable and non-separable cases as it does in discrete wavelet transform. Since the mothers introduced by the method in this paper are separable, they are included in the separable optical wavelet transform. And the advantages of the separable mothers are listed with corresponding examples.