Device for detecting light emission from optical fiber

Abstract

A device for determining the presence of light in an optical fiber includes a housing having a light-receiving chamber. An aperture in a wall of the housing accommodates insertion of the fiber into the chamber. A brush-configured, light-blocking curtain is mounted adjacent to the aperture and has a plurality of bristles sized and arranged to allow an optical fiber to pass therebetween. A funnel-shaped light reflector is disposed in the chamber adjacent to the curtain and has a first relatively wide diameter opening at a forward end thereof and tapers to a second, relatively narrow diameter light-exiting opening at an apex thereof. An opto-electronic light detector is disposed adjacent to the narrow diameter opening of the funnel-shaped light reflector. Light emitted by an optical fiber that has been inserted through the bristles of the light-blocking curtain impinges upon the opto-electronic light detector. At the same time, the bristles effectively wrap around the fiber and prevent entry of ambient light into the interior of the chamber and onto the light detector. A signal processing circuit is coupled to the output of the light detector generates an output representative of the presence of light in the fiber in response to the measured amount of optical energy exceeding a prescribed threshold.