DEVICE EMPLOYING DIFFERENTIAL DELAY OF PRINCIPAL AXES TO MEASURE POLARIZATION-MAINTAINING FIBER

摘要

Disclosed is a device employing a differential delay of principal axes to measure a polarization-maintaining fiber, comprising a polarization-maintaining fiber Sagnac interferometer, a signal generator, a microwave detector and a microprocessor. The polarization-maintaining fiber Sagnac interferometer comprises the following sequentially connected devices: a laser, an optoelectronic modulator, a polarization-maintaining fiber coupler, optical fiber interfaces J1 and J2 provided at an output end of the polarization-maintaining fiber coupler, a polarization-maintaining fiber under test provided between the optical fiber interfaces J1 and J2, and an optoelectronic detector provided at another output end of the polarization-maintaining fiber coupler. The signal generator generates a swept frequency radio frequency signal, and the swept frequency radio frequency signal is modulated onto an optical signal by the optoelectronic modulator. The microwave detector is used to detect a power of a radio frequency signal output by the optoelectronic detector. A microcontroller is connected to the microwave detector, and performs calculation according to an output signal of the microwave detector to obtain an optical delay of the polarization-maintaining fiber. The measurement device can achieve picosecond-precision measurement and a dynamic range of 1000 m.