Cutoff polarizer and method.

摘要

The cladding (32) and a portion of the core (30) of apparatus of a length of optical fiber are removed to form an interaction region where the fiber will not guide a light wave. A metal film (20) is placed on the exposed core and a portion of the cladding. Polarizations perpendicular to the metal film couple into the metal film to form a surface surface plasma wave that propagates parallel to the fiber while parallel polarizations radiate through the metal film. The surface plasma wave couples energy back into the fiber so that the throughput of the polarizer is only the perpendicular polarization component. A photodetector forms an error signal from the polarization radiated from the fiber, and control circuitry processes the error signal to drive a polarization controller that adjusts the polarization of light input to the polarizer to minimize the error signal and maximize the intensity of the desired polarization output from the polarizer.