Patent ID: 6728463
Filing Date: 2004-04-27
Classification: G02F

Abstract:
An optical attenuator, comprising:a first multi-mode waveguide that varies a phase of an optical signal input through an input terminal; first and second single-mode waveguides having an input terminal coupled to an output terminal of the first multi-mode waveguide and varying a phase of the optical signal by a thermo-optic effect by electrodes attached thereto; and a second multi-mode waveguide having an input terminal coupled to an output terminal of the first and second single-mode waveguides and varying a phase of the optical signal, wherein a predetermined optical power distribution is obtained by one of offsetting and adding a phase varied in the first and second multi-mode waveguides and a phase varied by the thermo-optic effect, and is transferred to an output terminal of the second multi-mode waveguide.