Tunable optical source for producing a coherent optical beam with a wide range of wavelength tuning

U.S. Patent Number: 5388106

Abstract: A tunable laser diode comprises a first reflector, a second reflector, an optical cavity extending between the first reflector and the second reflector for establishing an optical resonance by transmitting an optical beam therethrough, and a gain region for amplifying the optical beam. The optical cavity comprises a first waveguide part connected to the first reflector and extending toward the second reflector, a second waveguide part connected to the second reflector and extending toward the first reflector, a third waveguide part connecting the first waveguide part and the second waveguide part with each other for passing a first optical beam between the first and second reflectors, and a fourth waveguide part connecting the first waveguide part and the second waveguide part for passing a second optical beam between the first and second reflectors, wherein the first waveguide part, the second waveguide part and the third waveguide part form a first optical path having a first optical path length while the first waveguide part, the second waveguide part and the fourth waveguide part form a second optical path having a second optical path length that is different from said first optical path length. In correspondence to the third and fourth waveguide parts, a refractive index modulator is provided for changing a refractive index of the third waveguide part and the fourth waveguide part relatively with each other.

Inventors: Tabuchi; Haruhiko (Kawasaki, JP)

Assignee: Fujitsu Limited (Kawasaki, JP)

Application Number: 08/232,398

Issued: 1995-02-07

Expired: 2007-02-07

Classes: 372/20 ; 372/26; 372/46.01; 372/50.1

Field of search: 372/20,50,46,26

Click the image above to view patent images at uspto.gov within a frame.

Click here for the fulltext page on uspto.gov within a frame.