Research/Patents/US 4977546
US 4977546Tier 3 — General Defense

SIGNAL STABILIZATION IN OPTICAL HYDROPHONES

Assignee

US Government

Filed as: UNITED STATES OF AMERICA AS REPRESENTED BY THE SECRETARY OF THE NAVY

Filed

Jan 29, 1982

Granted

Dec 11, 1990

Location

NORWICH CT US

Abstract

A system for signal stabilizing in-phase modulated optical hydrophone arr employs interferometry with homodyne detection. Phase stabilization is accomplished by modulating the input laser signal in proportion to variations in the output of an optical transducer to balance the output phase so that the fringes are kept at optimum position. Additionally, fluctuations in light intensity are compensated for so that a photodetector responds only to phase shift variations. The technique used is to split the input beam into signal and reference beams using a beam divider, exposing the signal beam to the acoustic pressure of interest, recombining the signal beam with the reference beam, detecting the combined beams and filtering the resulting signal to separate out the acoustic information of interest from the phase shift and light intensity portions used to stabilize the input beam. The acoustic information is processed and the phase shift and light intensity information provides a feedback signal for use in input beam stabilization.

Source: Google Patents

35 USC §181 Secrecy Order

Imposed

Jun 29, 1982

Rescinded

May 4, 1990

Duration

7 years, 10 months

Inventor

  • 1JAMES P. FLATLEY

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Back to patent indexSource: USPTO 35 USC §181 secrecy order records