Patent ID: 7397567
Filing Date: 2008-07-08
Classification: G01J,G04G,H01S

Abstract:
1. A method for optical-radiofrequency phase detection, the method comprising: a) generating an optical pulse train; b) generating a radiofrequency electrical signal; c) detecting a portion of the optical pulse train and generating a first synchronous electrical detection signal; d) directing a second portion of the optical pulse train into a differentially biased Sagnac-loop interferometer; e) modulating the phase of the second portion of the optical pulse train in the differentially biased Sagnac-loop interferometer as a function of the frequency of the radiofrequency electrical signal; f) detecting an amplitude-modulated output of the Sagnac-loop interferometer and generating a second synchronous electrical detection signal; and g) synchronously detecting the second electrical detection signal with the help of the first electrical detection signal and generating a phase-error electrical signal having an amplitude proportional to the phase difference between the optical pulse train and zero-amplitude crossings of the radiofrequency electrical signal.