United States of America As Represented by the Secretary of the Air Force

Other

Raymond V Wick

Joseph M Geary

Dennis C Duneman

Charles E Moeller

Rex W Goranson

Ronald L Sessions

Darius S Vunck

A method of photographically recording at high speed the far field pattern of a high energy infrared laser beam over a selected period of time for providing rapid repetitive samples of information on beam parameters such as far field beam intensity, jitter, and absolute beam size and power. A sample from a high energy infrared laser beam is directed into an enclosure that is light tight to visible radiation and contains an operating lensless movie camera loaded with suitable movie film. The infrared beam is focused on the film plane of the camera so that consecutive frames of the film are irradiated by the infrared beam each time the camera shutter is open. The period of irradiation is of sufficient duration to sensitize the film to visible radiation in the areas where the infrared radiation impinges on the film. The position of the camera shutter is detected and an electrical trigger signal generated just before the shutter is closed for each frame. The trigger signal is applied to appropriate circuitry which actuates a light source to generate a pulse of visible light that irradiates the film plane of the camera near the end of each shutter movement to expose each frame of the film. The exposed film strip is developed to provide a continuous record of the infrared laser beam characteristics over the selected period of time.

Method and apparatus for high speed, sustained recording of infrared

An apparatus for converting a high intensity spatially coherent laser beam into a source of spatially incoherent radiation that retains the temporal, amplitude and frequency characteristics, and also the polarization, of the spatially coherent laser beam. A laser is oriented so that its coherent output beam falls on a transmissive optical lens which images the coherent beam onto the surface of a ground glass plate that has been etched with hydrofluoric acid to form a spatial diffuser. The radiation that emerges from the diffuser has been converted into spatially incoherent radiation that retains some important characteristics of the coherent beam, namely polarization and temporal coherence. The diffuser outputs a diverging beam of substantially incoherent radiation to a collimator that provides a collimated output beam that can be used in laser communicators, laser rangefinders and other laser field devices in an 'eyesafe' mode.

Eye safe laser transmitter

A bolometer for the detection of radiation includes a thin film of bismuth having electrical contacts formed at its outer boundary edge whereby electrical signals, as a function of the X and Y positions of input radiation, appear as output signals at the contacts. A measure of the radiant energy striking the detector is used to ratio X and Y to make the instrument insensitive to changes in power input.

Bolometer

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Albuquerque, NM, United States of America

Raymond V Wick