Polarization Insensitive 3x3 Sagnac Current Sensor Using Polarizing Spun High-Birefringence Fiber

摘要

The response functions of previously reported 3x3 Sagnac current sensors are strongly dependent on input polarization, so systems require careful control of the input polarization state. In this paper, the authors describe a simple method for eliminating this polarization dependence so that stable response functions are obtained. The authors demonstrate the existence of a wavelength range over which spun high-birefringence fiber guides only one elliptically polarized mode, thus preserving a single polarization state. Using this effect, the authors show that 3x3 Sagnac current sensor response functions can exhibit current sensing without the need for polarization control.