| 摘要 |
PURPOSE:To obtain fine switching characteristics even if the polarizing ratio of input light beams not sufficiently high by unitedly integrating a waveguide type polarizer on the input terminal side or output terminal side of a waveguide type optical switch element having dependency upon a polarizing surface, selecting only a light beam in a polarizing surface mode and inputting or outputting the selected light to/from the optical switch element. CONSTITUTION:It is supposed that the polarizing ratio of incident light beam is not sufficiently high and polarized light in a TE mode is inputted in addition to polarized light in a TM mode. The polarized light in the TM mode is outputted from an output optical waveguide 52, but a part of the TE mode polarized light made incident from an input optical waveguide 4 is leaked to an optical waveguide 61 of a connection part 51 because switching between the crossing state and straight state of an optical switch element 2 is not sufficiently executed. However, a polarizer 31 provides the crossing state to the polarized light in the TE mode and outputs the polarized light from an optical waveguide 71, so that the polarized light is prevented from leakage to an output optical waveguide 51 of the optical switch. Consequently, required switching operation for the TM mode polarized light can be attained independently of the TE mode polarized light of the input light. |
