Homodyne detection type photodetector

Abstract

Abstract PURPOSE:To simplify constitution and to improve photodetection characteristics by synchronizing an optical oscillator for light injection type local oscillation formed on the same substrate together with a directional coupler, etc. CONSTITUTION:A semiconductor substrate BP is provided with the light injection distribution feedback type optical oscillator OSC for light injection type local oscillation provided with a narrow interval grating for frequency selection together with the 1st and the 2nd directional couplers DRC1 and DRC2. Input signal light to this substrate BP is branched by the coupler DRC1 and incident to the oscillator OSC, which oscillates at a frequency synchronizing with the frequency of the injection light. The output of the oscillator OSC is supplied to the coupler DRC2 to obtain a local oscillation output, which is multiplied by input signal light propagated in a ight guide OPL and branched by the coupler DRC1 to obtain a beat component, which is inputted to a detector LDT to obtain a homodyne type detection signal. Therefore, the simple constitution which eliminates the need for a frequency stabilization part performs the stable homodyne detection to improve the reception characteristics.

Inventors

• 👤 Hideo Kuwabara
• 👤 秀夫 桑原

Bibliographic Details