Wavelength tunable semiconductor laser with narrow band-pass active filter region

Abstract

A semiconductor laser is disclosed in which a light emitting region having a light emitting layer and a waveguide region having a waveguide layer which is coupled to at least one side of the light emitting layer with a high efficiency are integrated on the same substrate; the light emitting region includes an active filter section having a diffraction grating equipped with a band-pass filter function; the light emitting region and the waveguide region are electrically isolated and are each provided with an electrode; and the oscillation wavelength of the semiconductor lase is changed by changing the refractive indices of at least the waveguide region and the active filter section through voltage application or current injection to the electrodes, thereby producing a narrow-linewidth, single-wavelength oscillation output light of a wavelength which corresponds to the transmission wavelength of the active filter section determined by the preset refractive indices of the waveguide region and the active filter section.

Dependencies are inferred from the claim text.