Optical filter
AssigneeSumitomo Electric Industries, Ltd.
InventorsHitoshi Hatayama, Masayuki Nishimura
Life of this patent
Estimating the term…
Abstract
A main optical path disposed between light input and output ends and an auxiliary optical path disposed so as to correspond to the main optical path are optically coupled to each other with first, second, and third optical couplers. The respective optical path lengths of main and auxiliary optical paths differ from each other between the first and second optical couplers and between the second and third optical couplers. Between the first and second optical couplers and between the second and third optical couplers, at least one of the main and auxiliary optical paths is provided with temperature adjusting means for adjusting the temperature of the corresponding optical path.
Claims5
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.
Dependencies are inferred from the claim text.