Quantum cascade laser, light emitting apparatus, method for fabricating quantum cascade laser

A light emitting apparatus comprising:

• a quantum cascade laser including
• a laser structure having a first region, a second region, and a third region, the first region having an end face;
• a high-specific resistance region disposed on the first region and the second region;
• a metal layer disposed on the third region;
• a dielectric film disposed on the end face and the high-specific resistance region;
• and
• a reflective metal film disposed on the dielectric film, the end face and the high-specific resistance region;
• a supporting base mounting the quantum cascade laser;
• and
• a solder material making contact with the metal layer of the quantum cascade laser to fix the quantum cascade laser to the supporting base,
• the first region, the second region, and the third region being arranged in order in a direction of an axis,
• the laser structure having a terrace with a difference in level disposed on a boundary between the second region and the third region, and
• the laser structure including a semiconductor mesa and a conductive base, the semiconductor mesa having a core layer, and the conductive base mounting the semiconductor mesa, and the high-specific resistance region having a specific resistance larger than that of the conductive base.

A method for fabricating a quantum cascade laser comprising:

• preparing a laser bar having an arrangement of device sections;
• supplying a flux of raw material for a dielectric insulator to a first end face of the laser bar to deposit dielectric insulator thereon;
• and
• after supplying the flux of the dielectric insulator, supplying a flux of raw material for a metal reflective film to the first end face of the laser bar to deposit the metal reflective film thereon,
• the laser bar including a laser structure and a high-specific resistance region, the laser structure having a first region, a second region, a third region, and a terrace, the first region having the first end face, and the high-specific resistance region being disposed on the first region,
• the first region, the second region, and the third region being arranged in order in a direction of a first axis and extending in a direction of a second axis intersecting that of the first axis, and
• the high-specific resistance region extending in the direction of the second axis, and
• the terrace having a difference in level extending on a boundary between the second region and the third region in the direction of the second axis.