Fred L Ellis

US Patent:

44052308, Sep 20, 1983

Filed:

May 28, 1981

Appl. No.:

6/267940

Inventors:

Claude E. Tew - Dallas TX
Fred E. Ellis - Plano TX

Assignee:

Texas Instruments Incorporated - Dallas TX

International Classification:

G01C 308
H01S 300

US Classification:

356 5

Abstract:

A heterodyne laser ranging system is disclosed which provides a waveguide housing which includes a first and second gas laser. The first laser is a low pressure laser while the second laser is a high pressure laser. These two lasers formed in the waveguide housing have their longitudinal axis in optical alignment. In the preferred embodiment, the second high pressure gas laser is a transversely excited atmospheric (TEA) laser. The first low pressure gas laser produces two outputs, one of the outputs is a low level local oscillator signal while the second output is transmitted as an input to the high pressure laser. The second high pressure laser builds up from the injected signal from the low pressure laser which results in a high pressure laser pulse output that has the frequency stability of the low pressure laser while maintaining the high peak power output available from a transversely pumped waveguide laser. The exitation of the low pressure laser continues throughout the length of time necessary to receive reflected energy from a target. The reflected energy from the target as well as the local oscillator output from the low pressure laser impinges on a detector which is utilized for heterodyne detection.

US Patent:

43085067, Dec 29, 1981

Filed:

Jun 4, 1979

Appl. No.:

6/045526

Inventors:

Fred E. Ellis - Plano TX

Assignee:

Texas Instruments Incorporated - Dallas TX

International Classification:

H01S 310

US Classification:

331 945Q

Abstract:

A fast acousto-optic Q-switch laser is taught comprising a lasing medium, reflecting means mounted substantially perpendicular to the longitudinal axis of the lasing medium and spaced from a first end thereof, feedback reflecting means spaced from a second end of the lasing medium, optical pumping means for pumping the lasing medium, an acousto-optic switch mounted along and tilted at a preselected angle with respect to the longitudinal axis of the lasing medium between the second end of the lasing medium and said feedback reflecting means and spaced from the second end of said lasing medium for deflecting a portion of the radiation emitted by the lasing medium, and first and second transducers mounted in opposition to each other on the switch, the first transducer mounted with respect to the switch such that the gradient of the envelope of the acoustic energy introduced into and propagated through the switch approximates the gradient of the non-uniform population inversion directly in the lasing medium, and the second transducer mounted with respect to the switch such that acoustic energy introduced into and propagated through the switch has a velocity vector opposite to the first transducer and timed to provide maximum feedback when lasing occurs, said feedback reflecting means positioned along and tilted at a preselected angle with respect to the longitudinal axis of said lasing medium related to the path to be taken by the deflected portion of radiation for reflecting said deflected portion of radiation back to said switch.