Patent ID: 6633698
Filing Date: 2003-10-14
Classification: G02F

Abstract:
An optical filter comprising:a main optical path for guiding light from an input end to an output end; an auxiliary optical path, optically coupled to said main optical path with three optical couplers composed of first, second, and third optical couplers, wherein the optical path length between said first and second optical couplers and an optical path length between said second and third optical couplers are different from said main optical path; two asymmetrical Mach-Zehnder interferometers combined with said three optical couplers and sharing said second optical coupler; first temperature adjusting means, disposed in at least one of said main and auxiliary optical paths between said first and second optical couplers, for adjusting the temperature of said main and/or auxiliary optical paths; second temperature adjusting means, disposed in at least one of said main and auxiliary optical paths between said second and third optical couplers, for adjusting the temperature of said main and/or auxiliary optical paths; and control means for controlling said first and second temperature adjusting means so as to set a slope of transmission loss across said main optical path to wavelength in a given wavelength band.