OPTICAL DEMULTIPLEXER AND MULTIPLEXER

摘要

PURPOSE:To switch and send light with specific wavelength incident on a polarization splitter out of the polarization splitter in a specific direction by applying a voltage signal which causes electrooptic effect selectively with respect to light with specific wavelength passed through an electrooptic element between groove-shaped electrodes. CONSTITUTION:An optical coupling part CP separates light incident on the polarization demultiplexer 7 through a lens 5 into an S and a P wave; the P wave is incident on a PLZT9 and the S wave is incident on a PLZT8 respectively. Neither of the PLZTs 8 and 9 causes electrooptic effect unless a control voltage is applied, so the P wave passed through the PLZT9 and the S wave passed through the PLZT8 are both outputted to an optical fiber 16 through a lens 12. When a specific voltage corresponding to the wavelength of the incident light is applied between electrodes of the PLZTs 8 and 9 from a control means 18, electrooptic effect is caused and the P wave and S wave passed through there have planes of polarization rotated by 90 deg. and becomes an S and a P wave respectively. Consequently, the light made into the P wave through the PLZT8 and the light made into the S wave through the PLZT9 are both incident on the polarization multiplexer 11 and then outputted to the optical fiber 17 through a lens 12.