A New Design and Feedback Control of a Fiber Michelson Interferometer to Detect High Frequency Vibration with Style of Noncontact

Fiber interferometry is an important means in sensing field. The phase shift affects the sensitivity of interferometry and high frequency signals are hardly detected by fiber itself. A feedback control system based on proportional-integral-derivative algorithms was used to stabilize the phase. Meanwhile, a three ports circulator and two attenuators were added in the Michelson interferometry to improve the interference signal. Also, a self-built fiber focused head was employed to convert fiber light to space light in the end of detection path. With the presented approaches, we stabilized the phase and detected a high frequency vibration of 1.7 MHz.