Patent ID: 7162120
Filing Date: 2007-01-09
Classification: G02B,H04B

Abstract:
1. A tunable dispersion compensator comprising: a mode filter which inputs an optical signal, removes high-order modes of said optical signal and outputs only a fundamental mode; a resonator which inputs the optical signal output from said mode filter and outputs said optical signal with a delay time added; and tunable controlling means for controlling said resonator in a tunable manner; wherein said mode filter and said resonator are constructed of optical waveguides on substrates and said tunable controlling means is disposed in the vicinity of said waveguides; wherein said resonator is a ring resonator comprising: a linear waveguide; a ring-shaped waveguide arranged along said linear waveguide; and an optical coupler which optically couples said linear waveguide and said ring-shaped waveguide, and said mode filter is disposed on said linear waveguide on at least one of the input side and output side of said ring resonator; and wherein said mode filter includes a curved area where high-order modes are emitted and only the fundamental mode is transmitted and said curved area is disposed along the perimeter of said ring-shaped waveguide.