Accession Number:

AD0668509

Title:

NONSELECTIVE OPTICAL-ACOUSTIC RECEIVER WITH AN OPTICAL MICROPHONE,

Descriptive Note:

Corporate Author:

FOREIGN TECHNOLOGY DIV WRIGHT-PATTERSON AFB OHIO

Personal Author(s):

Report Date:

1967-06-16

Pagination or Media Count:

34.0

Abstract:

The paper describes a non-selective optico-acoustic receiver of infrared radiation. The instrument consists of a radiation absorption chamber and an optical microphone. A diagram of the optical system is shown. An intermittent stream of radiation passes through fluorite window and is absorbed by a thin layer of aluminum applied to an extremely thin celluloid substrate, which is located in the optico-acoustic chamber. Pressure pulsations are generated by absorption of the radiation in the chamber. These pulsations cause celluloid diaphragm to oscillate. This diaphragm, which is coated with a reflecting layer of antimony, is simultaneously one of the walls of the chamber and also the diaphragm of the microphone. A transparent glass grating is located in the focal plane of lens, which is separated from diaphragm by a distance of 15 mm. An image of light source is projected through the grating onto the diaphragm by condenser lens. This image is then reflected through the second half of the grating to mirror and from there through iris to single-stage photomultiplier. The vibration of the microphone diaphragm causes a periodic displacement of the image along the optical axis which results in oscillations of the light flux sent from the auxiliary source to the photomultiplier. Author

Subject Categories:

  • Optics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE