Patent ID: 11909173
Assignee: FURUKAWA ELECTRIC CO., LTD.
Field: Optics (Instruments)
Classification: CPC H | IPC H

Claim 0:
1. A waveguide based wavelength-tunable laser formed on a semiconductor substrate, the wavelength-tunable laser comprising:
a first reflector from which laser light is output;
a second reflector configuring a laser resonator together with the first reflector;
a gain portion that is provided between the first reflector and the second reflector;
at least two wavelength filters that can adjust wavelength characteristics and adjust a wavelength of the laser light;
a phase adjuster that adjusts an optical path length in the laser resonator, wherein
a folded portion configured by a waveguide that folds back an optical path by an angle of substantially 180 degrees is provided between the first reflector and the second reflector; and
a semiconductor optical amplifier that is provided on a laser light output side of the first reflector on the semiconductor substrate, wherein at least one of the two wavelength filters and the phase adjuster has a refractive index that is adjusted by a heater and is arranged to be separated from the semiconductor optical amplifier by a distance larger than a thickness of the semiconductor substrate.