Arbitrary Phase-locking In Mach-Zehnder Interferometer

Phase locking technology is widely used in many fields,including electronics and photonics.Precision measurement technology plays a decisive role in social development,daily life,national defense security and other fields.Optical interference technology is the most commonly used and highly accurate measurement method in precision measurement technology.In recent years,with the rapid development of optical precision measurement technology,the phase stability of optical interferometer becomes more and more important,which directly determines the accuracy of measurement.Phase locking between two interferometric arms becomes an indispensable technique in the field of optical precision measurement.In this paper,we proposed and designed a locking method for any phase point in a period based on Mach-Zehnder optical interferometer.The whole locking device is simple,easy to operate and stable in operation.The core element is electro-optic modulator(EOM),which can generate different phase shift on the vertically polarized light and horizontally polarized light.In the specific experiment,EOM and PID feedback are used to realize the fast,accurate and long-term locking of any phase point within a period,and the light intensity of the output end of the interferometer is stable.Our experimental results show that the precision of phase lock can control within 1.05 ° or 0.0029.The phase-locking technology has potential applications in the field of precision measurement in the future.