Polarization-maintaining Fiber Coupler

https://www.meisuoptics.com/polarizationmaintaining-fiber-coupler-is-one-of-the-basic-components-of-high-precision-fiber-sensor.html

The polarization maintaining coupler is a key component to realize the coupling, splitting and multiplexing of linearly polarized light. Its characteristic is that it can stably transmit two orthogonal linearly polarized lights and keep their respective polarization states unchanged, thus becoming key optic devices for various military interference sensors, coherent optical communications, fiber optic gyroscopes, and fiber optic hydrophones etc.