WAVEGUIDE TYPE OPTICAL MULTIPLEXING/DEMULTIPLEXING CIRCUIT

摘要

PURPOSE:To multiplex and demultiplex optical waves with a high precision by specifying a half of the angle made between an optical waveguide for input and that for output on which a reflected light is made incident. CONSTITUTION:A band-pass filter 51 is used to demultiplex light having wavelengths lambda2 and lambda3 and is used on the condition of theta=10 deg. (theta is the filter angle) for the purpose of securing the demultiplexing characteristic. When mixed light having three kinds of waveform lambda1-lambda3 is made incident on an optical waveguide 20 for input, the light having the wavelength lambda1 is transmitted through a short wavelength pass filter 50 and is branched to an optical waveguide 22 for output. Light having wavelengths lambda2 and lambda3 reflected on the filter 50 is propagated in an optical waveguide 23 and reaches the band-pass filter 51, and the light having the wavelength lambda2 is reflected on the filter 51 and is propagated in an optical waveguide 26 and is transmitted through a band-pass filter 52 and is emitted from the end of a waveguide 27 for output. The light having the wavelength lambda3 transmitted through the filter 51 passes a band-pass filter 53 and is emitted from an optical waveguide 25 for output to the outside of substrate.