Title :
Broad-band high-silica optical waveguide star coupler with asymmetric directional couplers
Author :
Yanagawa, Hisaharu ; Nakamura, Shiro ; Ohyama, Isao ; Ueki, Ken
Author_Institution :
Furukawa Electr. Co. Ltd., Chiba, Japan
fDate :
9/1/1990 12:00:00 AM
Abstract :
A broadband optical waveguide star coupler with asymmetric directional couplers is proposed. A coupling or splitting ratio of the coupler is flattened with respect to wavelength by choosing appropriate values for Δβ and complete power transfer length. The wavelength characteristics of uniform and alternating Δθb directional couplers are investigated, and their broadband operation is shown theoretically. To demonstrate the feasibility of the new proposal, 8×8 star couplers composed of such asymmetric directional couplers are fabricated by using high-silica waveguides on a silicon chip. A star coupler composed of asymmetric directional couplers exhibited 2-dB loss variation in the wavelength range of 1.3-1.55 μm, and this value was almost one fourth of that of a star coupler composed of symmetric directional couplers
Keywords :
directional couplers; integrated optics; optical couplers; optical fibres; optical losses; 1.3 to 1.55 micron; Si chip; asymmetric directional couplers; broad band high SiO2 optical waveguide star coupler; broadband operation; complete power transfer length; loss variation; splitting ratio; wavelength characteristics; wavelength range; Directional couplers; Optical coupling; Optical device fabrication; Optical fiber couplers; Optical losses; Optical refraction; Optical switches; Optical variables control; Optical waveguide theory; Optical waveguides;
Journal_Title :
Lightwave Technology, Journal of
