Semiconductor laser element, semiconductor laser device, semiconductor laser device manufacturing method, and gas analysis device

Abstract

The present invention enables single mode light to be stably output while also enabling the intensity thereof to be increased, and is a distributed feedback type of semiconductor laser element in which a diffraction grating is formed on a waveguide. The waveguide includes a diffraction grating portion where the diffraction grating is formed, and a flat portion having a region where the diffraction grating is not formed and whose width is broader than the diffraction grating portion. The flat portion has a connecting portion having a region whose width changes continuously approaching a connection location with the diffraction grating portion, and a high-reflection film is provided on an end surface of the flat portion that is on an opposite side from the connecting portion, while an anti-reflection film is provided on an end surface of the diffraction grating portion that is on an opposite side from the connecting portion.

Dependencies are inferred from the claim text.