| 摘要 |
An improved solution to achieving low PDL and low PDM in wavelength selective filter devices for use in fiber optic communications systems is disclosed. In one embodiment, an optical input signal is divided into orthogonal polarization components by a polarizing beam splitter. The two polarization components are provided to an Electrically Switchable Bragg Grating (ESBG) device. The polarization of one of the two components is rotated ninety degrees such that the two components enter the ESBG device having the same polarization orientation. At the output of the ESBG device, one of the two components is rotated ninety degrees, such that the polarization of the component so rotated is orthogonal to the polarization of the other component. The two components are then combined, using a polarizing beam combiner, and the combined signal is provided as an optical output signal.
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