Optical variable attenuator and optical module

摘要

An optical variable attenuator has a planar waveguide, which is provided with optical waveguides forming an input optical line A and an output optical line B. A cantilever is disposed at the upper face of the planar waveguide, whereas a movable mirror for reflecting light passing through the input optical line A toward the output optical line B is secured to the leading end part of the cantilever. An electrode is disposed at the upper face of the planar waveguide. The cantilever and the electrode are connected to each other by way of a voltage source. The voltage source applies a voltage between the cantilever and the electrode, so as to generate an electrostatic force therebetween, which flexes the leading end side of the cantilever toward the electrode. As a consequence, the movable mirror moves toward the electrode.