Robert Wayne Duvall

US Patent:

46602046, Apr 21, 1987

Filed:

Aug 2, 1984

Appl. No.:

6/637097

Inventors:

Donald R. Dewhirst - Torrance CA
Robert L. Duvall - Torrance CA

Assignee:

Hughes Aircraft Company - Los Angeles CA

International Classification:

H01S 3125

US Classification:

372 16

Abstract:

A CO. sub. 2 TEA laser utilizing an intra-cavity rotating prism Q-switch (70) for angularly switching the resonator gain by periodically causing the resonator mirrors (54, 56) to be in alignment. An opto-electronic timing device (79), which includes a graded index glass rod (76) rotating with the Q-switch prism, generates a pulse to initiate the laser discharge at the proper time before the mirrors are aligned so that the laser output pulse occurs when peak gain is achieved. The Q-switch speed of rotation is chosen such that the time interval in which the mirrors are aligned is not long enough to support the tail portion of the pulse typical of the gain switched CO. sub. 2 TEA laser.

US Patent:

46662952, May 19, 1987

Filed:

Jul 3, 1984

Appl. No.:

6/627704

Inventors:

Robert L. Duvall - Torrance CA
Maurice J. Halmos - Los Angeles CA
David M. Henderson - Playa del Rey CA

Assignee:

Hughes Aircraft Company - Los Angeles CA

International Classification:

G01C 300
H01S 300
G01S 728

US Classification:

356 5

Abstract:

A laser radar system employing a linear FM chirp laser followed by post detection pulse compression by a surface acoustic wave (SAW) device. The system includes an FM chirp modulator that provides the needed tuning range and linearity for pulse compression. This modulation is accomplished by using a high-pressure CO. sub. 2 laser with an intracavity electro-optic modulator of CdTe. The frequency of the transmitter laser is accurately controlled through the application of high linearity, high frequency, sawtooth voltages to the two plates of the CdTe crystal, with the voltage waveform applied to one plate being out of phase with that applied to the other crystal plate. With the performance the system offers, absolute radar ranges can be measured to 0. 22 m and velocities to 0. 37 m/sec.

US Patent:

52586197, Nov 2, 1993

Filed:

Nov 18, 1987

Appl. No.:

7/129520

Inventors:

Robert L. Duvall - Torrance CA

Assignee:

Hughes Aircraft Company - Los Angeles CA

International Classification:

G01J 500
H01J 4014

US Classification:

2503381

Abstract:

Methods and apparatus are disclosed for broadening the bandwidth of a radiation detector and diminishing heat generated noise generated within the detector in order to enhance detectivity. The improved performance is achieved by applying a pulsed bias to the detector which consists of a sequence of waveforms which reduces the duty cycle of the detector in comparison to a detector subjected to a constant bias. A sophistication of this use of a pulsed bias is the utilization of a swept bias which employs a sequence of waveforms having gradual rise-times which further reduces unwanted detector noise and enhances detectivity.

US Patent:

46627413, May 5, 1987

Filed:

Mar 17, 1983

Appl. No.:

6/476288

Inventors:

Robert L. Duvall - Torrance CA
Maurice J. Halmos - Los Angeles CA
David M. Henderson - Playa del Rey CA

Assignee:

Hughes Aircraft Company - Los Angeles CA

International Classification:

G01C 308
G01P 336
H01S 300

US Classification:

356 5

Abstract:

A laser radar system employing a linear FM chirp laser followed by post detection pulse compression by a surface acoustic wave (SAW) device. The heart of the invention is the FM chirp modulator that provides the needed tuning range and linearity for pulse compression. This modulation is accomplished by using a high pressure CO. sub. 2 laser with an intracavity electric-optic modulator of CdTe. The frequency of the laser is controlled through the voltage applied to the crystal. With the performance the system offers, absolute radar ranges can be measured to 0. 22 m and velocities to 0. 37m/sec.

Author:

Robert Duvall

ISBN #:

0425166074