Storage Technology Corporation

Santa Barbara Research Center

Dennis Rose

Paul S Sugino

Leonard Laub

Charles Reilly

Ed Russell

An apparatus (10) and method for testing the continuity of two optical fibers (12, 14) nonsimultaneously utilizing a single optical path. Two test light beams from a dual hybrid laser (30) are collimated and directed down a single optical path time-sequentially. The two light beams are linearly polarized in orthogonal planes. A quarter wave plate (42) converts the linearly polarized light into circularly polarized light, and an optical sequencer (22) directs the circularly polarized beams to a plurality of desired optical paths, each path comprising one or two optical fibers (12, 14). A second quarter wave plate (50) converts the circularly polarized light back into linearly polarized light, and a polarizing beamsplitter (24) reflects one of the beams and transmits the other. The two beams then enter the optical fibers (12, 14), where they are reflected by dichroic mirrors (26, 28) at the opposite end of the fibers (12, 14). The reflected beams retrace the original optical paths until they are reflected by a beamsplitter (38) which directs the beams onto a photodetector (58 ). The intensity of the light pulse detected by the photodetector (58) will indicate the continuity of the fibers (12, 14). Using this invention, measurements of the continuity of the two fibers (12, 14) can be made separately, resulting in increased sensitivity over methods which measure the two fibers (12, 14) simultaneously.

Separation of simultaneous events in a laser firing unit using a

Apparatus for reading information stored in a track pattern on a radiation reflecting record comprises a source of radiation such as a laser for supplying at least a reading beam, an objective lens assembly for passing the reading beam to the record and for controllably focusing the reading beam at a plane of focus, a photodetector array disposed in an optical path with the lens assembly for sensing at least the recorded information and focusing errors, and an astigmatic element disposed in the optical path for producing an astigmatic image of the reading beam in which the photodetector array comprises a unitary data photodetector disposed for impingement thereon of a zero order reading beam component for sensing the recorded information, and a quadrant photodetector array adjacent to the unitary data photodetector and including separated sectors disposed along orthogonal axes for sensing relative differences of the astigmatic image along the orthogonal axes to provide at least focus error correction signals to the objective lens assembly.

Growing community of inventors

Claremont, CA, United States of America

Dennis Rose