Optical modulator

摘要

Disclosed herein is an optical modulator module including an optical waveguide structure of a Mach-Zehnder type, for example, an electrode for switching a coupling mode where an output beam is obtained from the optical waveguide structure and a leakage mode where a leakage beam deflects from the optical waveguide structure, a photodetector having a photodetecting surface for receiving the leakage beam, and a mechanism for converting a beam parameter of the leakage beam so as to prevent close contact of the photodetecting surface with the optical waveguide structure. The optical modulator module allows monitoring of optical power by the use of the leakage beam and is improved in manufacturability.