Abstract

Polarization-maintaining fiber is finding an increasing number of applications in fiber-optic-based technologies such as coherent detection systems, fiber Raman amplifiers, fiber-optic sensors, and gyroscopes. As a result more attention is directed toward fiber-optic components which are compatible with polarization-maintaining systems. One such component Is a polarization-selective coupler (PSC).^1,2 This device is designed to combine the light output from two polarization-preserving fibers (the two outputs having orthogonal linear polarization states) into a single fiber. In the opposite direction the PSC is a polarization-selective splitter, splitting the output from a single fiber into two polarization-maintaining fibers each with orthogonal linear polarization states. The advantages of a PSC are that both polarization states are maintained, and there is no inherent excess splitting loss of 3.0 dB, which is characteristic of the 3-dB splitters made with a standard single-mode fiber. Applications of the PSC include an in-line fiber polarizer, polarization multiplexer (demultiplexer), polarization monitor or tap, and passive device for providing laser redundancy.

© 1987 Optical Society of America