| 摘要 |
A quantum cascade laser includes a semiconductor substrate, and an active layer that is provided on the substrate, and has a cascade structure in which emission layers and injection layers are alternately laminated by multistage-laminating unit laminate structures each consisting of the quantum well emission layer and the injection layer, and generates light by intersubband transition in a quantum well structure. Further, in a laser cavity structure for light with a predetermined wavelength to be generated in the active layer, CeO2 insulating films and reflection control films are formed in order on respective faces of a first end face and a second end face facing each other. Thereby, it is possible to realize a quantum cascade laser capable of preferably realizing reflectance control for light within a mid-infrared region on the laser device end face. |
