Patent ID: 8837548

Claim:
A semiconductor optical element comprising; an optical amplifier; a plurality of first reflectors, formed on a substrate, that reflect lights input from their respective input ports, return them to the input ports, and exhibit a reflection spectrum featuring a peak at a target wavelength; a first optical coupler, formed on the substrate, that divides light output from the optical amplifier and inputs the divided lights to the input ports of the plurality of first reflectors, combines the lights reflected from the plurality of first reflectors, and re-inputs them to the optical amplifier; and a second reflector that, together with each of the first reflectors, defines an optical resonator containing the optical amplifier and optical coupler; wherein each of the first reflectors contains a ring resonator of the same size and the delay time for the light input from the input port to return there after being reflected is the same for all first reflectors.