| 摘要 |
PROBLEM TO BE SOLVED: To make a circuit size small by suppressing influence of thermal crosstalk on adjacent channels in a multichannel thermooptic variable attenuator constituted by arranging a plurality of variable attenuators, where heaters for shifting the phase of light by thermooptic effect are arranged in parallel on arm waveguides of a Mach-Zehnder interference circuit (MZI circuit) using two couplers. SOLUTION: The multichannel thermooptic variable attenuator has a heat conductive layer made of a substance having high heat conductivity below the arm waveguide pair constituting the MZI circuit separately from a heat conductive layer provided below an adjacent MZI circuit, and also has a heat insulating layer made of a substance having lower heat conductivity than each heat conductive layer below the heat conductive layer. COPYRIGHT: (C)2007,JPO&INPIT |
