Laser pulse detection method and apparatus

US4669882A · kind A · utility

Assignee

• The United States of America as represented by the Administrator of the National Aeronautics and Space Administration · US

Inventors

• Willis C. Goss · Altadena, US
• James Robert Janesick · Tecate Mission Road, US

Key dates

• Filing date: Feb 22, 1984
• Grant date: Jun 2, 1987
• Expiry date: Feb 22, 2004

Classification

• Technology area (CPC G): Physics
• CPC primary: G01C19/72
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A sensor is described for detecting the difference in phase of a pair of returned light pulse components, such as the two components of a light pulse of an optical gyro. In an optic gyro, the two light components have passed in opposite directions through a coil of optical fiber, with the difference in phase of the returned light components determining the intensity of light shining on the sensor. The sensor includes a CCD (charge coupled device) that receives the pair of returned light components to generate a charge proportional to the number of photons in the received light. The amount of the charge represents the phase difference between the two light components. At a time after the transmission of the light pulse and before the expected time of arrival of the interfering light components, charge accumulating in the CCD as a result of reflections from optical components in the system, are repeatedly removed from the CCD, by transferring out charges in the CCD and dumping these charges.