Peter A. Wasilousky

Active compensation for transient thermal effects in acousto-optic devices

Verfahren zur Kompensation thermischer transienter Effekte in einem akustooptischen Medium in einem akustooptischen Gerat mit mindestens einem Signaleinkoppel-Wandler, der mit der Oberflache des akustooptischen Mediums gekoppelt und zum Empfangen elektrischer Signale zur Modulation mindestens einer in das akustooptische Medium eingekoppelten Schallwelle ausgefuhrt ist, wobei – mindestens ein elektrothermisches Element mit dem akustooptischen Medium nahe dem mindestens einen Signaleinkoppel-Wandler gekoppelt wird, und – als Reaktion auf die Beaufschlagung des akustooptischen Mediums mit Schallenergie durch mindestens einen Signaleinkoppel-Wandler mittels eines Komparators, an dessen Ausgang elektrische Signale als Funktion (i) eines vorgeschriebenen Pegels, der die elektrische Energie reprasentiert, mit der das elektrothermische Element zu beaufschlagen ist, und (ii) der elektrischen Energie, mit der das akustooptische Medium von dem mindestens einen Signaleinkoppel-Wandler beaufschlagt wird, erzeugt werden, und – die elektrischen Signale zur Ansteuerung des mindestens einen elektrothermischen Elements eingesetzt werden, wodurch dieses mit elektrischer Energie beaufschlagt und die...

Quantum enhancement of a coherent ladar receiver using phase-sensitive amplification

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.

High-performance optical vector-matrix coprocessor

This paper describes the design and fabrication of a high performance optical vector-matrix 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 MHz--effectively 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.

Preliminary characterization of a hybrid optical-digital ISAR processor

We previously reviewed the architecture and basic analytic results for a hybrid optical-digital processor capable of generating target range Doppler profiles in real time. Here we describe the optical design and present preliminary results for the optical correlator portion of the hybrid system. Phase control, fringe stability, and preliminary correlation data for the optical system are reported.

Characterization of wideband ISAR processor

We review the basic operating principles involved in development of a real time hybrid opto-electronic radar processor to form a 2-D range-Doppler image for ISAR applications. An overview description of the physical implementation of the processor developed at PSI is included, along with a discussion of the high level processor control structure required for performing the radar algorithm and system test functions. Finally, we present the results of preliminary testing of the pulse compression processor (PCP) which forms the cornerstone of the optical processing operation. The key capability of the optical correlator to map precise phase shifts via direct control of the radar transmitter carrier IF is demonstrated.

Optoelectronic radar receiver for real-time radar imaging

We have previously presented the architecture and basic analytic results for a functional 1D pipelined hybrid optical/digital processing concept capable of generating a target range- doppler profile in real time. Here we address the fundamental system processing algorithm and hardware development issues in some detail. The approach to performing real-time phase correction of the individual range profiles is outlined, along with the basic system operational runtime algorithms and system processing pipeline. A description of the receiver hardware and its component functionality in terms of the presented operational theory is given as well.