Programmable optical switch apparatus

摘要

An optical switch comprises a programmable optical polarization unit (POLCON) which receives an input optical signal and selects an output signal polarization in response to a control signal. A polarization beam splitter (PBS) splits the selected polarization signal from the POLCON into a first and second orthogonally polarized signals. A feedback circuit couples a feedback signal indicative of the optical signal strength of at least one of the orthogonally polarized signals back to the POLCON which uses it to adjust the output signal polarization. The optical switch may be used with input optical signals having fixed or varying polarizations by utilizing a single or two feedback signals, respectively. The optical switch may be used as an optical Add/Drop unit or incorporated as part of a wavelength division multiplexed (WDM) signal Add/Drop unit. <IMAGE>