A system has been developed to accurately detect phase signals produced in optical interferometric sensors. The system employs optical heterodyning and synchronously detects optical phase by feeding back an error signal to a phase modulator in the reference leg of the interferometer. This system is seen to have properties similar to a phase-locked loop. The system is mathematically analyzed and a simple second-order model developed which accurately predicts the system response.
© 1983 Optical Society of America
I. Jeffrey Bush and Ronald L. Phillips, "Synchronous phase detection for optical fiber interferometric sensors," Appl. Opt. 22, 2329-2336 (1983)