Gated fiber optic transmission
Abstract
A gated fiber optic sensor system is disclosed for increasing the effective optical path of a length of optical fiber cable. A pulse of polarized light having a known optical wavelength is directed into a length of optical fiber cable for propagation therethrough in a cyclic path. A planar semiconductor member is mounted in the path of the polarized light pulse at the Brewster angle to permit continuous transmission of the polarized light pulse through the cable until a light pulse of a second optical wavelength is made to impinge upon the semiconductor member, changing the reflectivity characteristics thereof and causing the polarized pulse to be extracted from its cyclic path for detection and processing. In one preferred embodiment, the optical fiber cable is configured in a loop to provide the cyclic path for the polarized light pulse, while in another preferred embodiment, the pulse path is provided by a straight section of optical fiber cable forming a part of a highly reflective cavity having reflectors on either end.
- Publication:
-
Patent Department of the Navy
- Pub Date:
- May 1984
- Bibcode:
- 1984navy.reptQ....B
- Keywords:
-
- Fiber Optics;
- Light Transmission;
- Optical Paths;
- Brewster Angle;
- Electromagnetic Pulses;
- Gates (Circuits);
- Optical Fibers;
- Patents;
- Reflectance;
- Semiconductors (Materials);
- Optics