We demonstrate a balanced-homodyne LADAR receiver employing a phase-sensitive amplifier (PSA) to raise the effective photon detection efficiency (PDE) to nearly 100%. Since typical LADAR receivers suffer from losses in the receive optical train that routinely limit overall PDE to less than 50% thus degrading SNR, PSA can provide significant improvement through amplification with noise figure near 0 dB. Receiver inefficiencies arise from sub-unity quantum efficiency, array fill factors, signal-local oscillator mixing efficiency (in coherent receivers), etc. The quantum-enhanced LADAR receiver described herein is employed in target discrimination scenarios as well as in imaging applications. We present results showing the improvement in detection performance achieved with a PSA, and discuss the performance advantage when compared to the use of a phase-insensitive amplifier, which cannot amplify noiselessly.

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1. ABSTRACT This paper describes the design and fabrication of a high performance optical vectormatrix coprocessor for optical computing research applications. The optical vector-matrix coprocessor is configured to multiply an 8-element vector by an 8 X 8 matrix with a throughput rate of 1 MHzeffectively achieving a processing rate of over 100 Mops. The Vector-Matrix Coprocessor interfaces to an industry standard Personal Computer with a single card and is controlled by software written and compiled in the ANSI C language. All data input and output to the coprocessor are in 8 bit digital words. An 8 to 12 bit look up table is provided for each input channel to provide real time linearization of analog optical data representing input values through the optical system. The optical signals representing calculation values are detected and received by a switched capacitor integrating filter to reduce detection bandwidth and reject broadband noise. INTRODUCTIONOptical matrix processors were developed to exploit the high degree of parallel connectivity inherent in free space optical interconnection. Researchers have proposed and investigated optical algebra processors for at least three decades1'2. Many different architectures and implementations have been investigated in as many different laboratories. Recent advances in multi-channel modulators3, light valve technology, and detectors4 have potential to make these systems practical for many applications. Specifically, vector-matrix processing can give much higher throughput than digital approaches and many applications exist were performance can be bought with speed even at the price of accuracy or dynamic range5'6. Earlier works have developed similar and more powerful processors, but have used expensive and bulky approaches that rely on pulsed lasers7 or systolic algorithms8 that limit their application to very special missions. This paper describes the development of a high performance Optical Vector MatrixCoprocessor that is constructed as much as possible with off-the-shelf components. It incorporates advances in optical technology for its laser source, vector modulator and detector array while leveraging the increased the performance and reduced cost of the new wave of digital electronics. The state of the art of digital to analog to digital conversion is increasing daily to meet the promise of digital video to the home. The practical application of photonic systems has greater promise due to the steady development of its component technology. The OVMC is designed to use these advances for a flexible and programmable test bed to aid the development a new generation of processors. Further, its architecture is chosen to be simple and to be applied to a much smaller package volume for its application to a large range of missions were a linear algebra coprocessor is only a part of a much larger system.

We describe a 500 MHz, 2 microsecond time aperture, Liro03 acousto -optic Bragg cell with minimal acoustic beam spreading and high diffraction eficiency.The cell utilizes an apodized phased array transducer. This device is particularly useful in wide bandwidth acousto -optic processing applications, such as optical correlation, where diffracted optical beam quality is important. AbstractWe describe a 500 MHz, 2 microsecond time aperture, LiNb03 acousto-optic Bragg cell with minimal acoustic beam spreading and high diffraction efficiency.The cell utilizes an apodized phased array transducer. This device is particularly useful in wide bandwidth acousto-optic processing applications, such as optical correlation, where diffracted optical beam quality is important.

Optical matrix processors were developed to exploit the high degree of parallel connectivity inherent in free space optical interconnection. Researchers have proposed and investigated optical algebra processors for at least three decades1,2. Recent advances in multi-channel modulators’ vertical cavity surface emitting laser (VCSEL) diode arrays, light valve technology, and detectors have potential to make these systems practical for many applications. Specifically, vector-matrix processing can give much higher throughput than digital approaches and many applications exist were performance can be bought with speed even at the price of accuracy or dynamic range3,4.