Patent ID: 6545785
Filing Date: 2003-04-08
Classification: H04B

Abstract:
An optical communication system using a radio frequency (RF) signal for communicating an analog communication signal comprising:an optical transmitter comprising: means for generating a reference light beam; means for generating a shifted light beam that is shifted in frequency relative to the frequency of said reference light beam by a predetermined radio frequency (RF); and means responsive to the analog communication signal and operative to produce a communication light beam having phase modulation corresponding to the analog communication signal; and an optical receiver comprising: first means responsive to said reference light beam and said shifted light beam and operative to interferometrically combine said reference light beam with said shifted light beam to provide a first heterodyne signal; second means responsive to said first heterodyne signal and operative to produce a first electrical signal at the optical beat frequency corresponding to the RF; third means responsive to said communication light beam and said shifted light beam and operative to interferometrically combine said communication light beam with said shifted light beam to provide a second heterodyne signal including information regarding the state of phase of the communication light beam; fourth means responsive to said second heterodyne signal and operative to produce a second electrical signal at the optical beat frequency corresponding to the RF and with a phase corresponding to the state of phase of the communication light beam; and fifth means responsive to said first and said second electrical signals and operative to provide an output signal that has a linear correspondence to the state of optical phase of said communication light beam and the analog communication signal.