QUANTUM CASCADE LASER

摘要

A quantum cascade laser is configured with a semiconductor substrate, and an active layer provided on a first surface of the substrate and having a multistage lamination of unit laminate structures each of which includes an emission layer and an injection layer. The active layer is configured to be capable of generating first pump light of a frequency ω1 and second pump light of a frequency ω2, and to generate output light of a difference frequency ω by difference frequency generation. An external diffraction grating is provided constituting an external cavity for generating the first pump light and configured to be capable of changing the frequency ω1, outside an element structure portion including the active layer. Grooves respectively formed in a direction intersecting with a resonating direction are provided on a second surface of the substrate.

主权项

1. A quantum cascade laser comprising:
a semiconductor substrate; and an active layer provided on a first surface of the semiconductor substrate and having a cascade structure in which quantum well emission layers and injection layers are alternately stacked in the form of a multistage lamination of unit laminate structures each of which comprises the quantum well emission layer and the injection layer, wherein the active layer is configured to be capable of generating first pump light of a first frequency ω1 and second pump light of a second frequency ω2 by intersubband emission transitions of electrons, and to generate output light of a difference frequency ω between the first frequency ω1 and the second frequency ω2 by difference frequency generation from the first pump light and the second pump light, an external diffraction grating is provided constituting an external cavity for generating the first pump light by feeding the light of the first frequency ω1 back to an element structure portion and configured to be capable of changing the first frequency ω1, outside the element structure portion including the active layer provided on the first surface of the semiconductor substrate, and a plurality of grooves respectively formed in a direction intersecting with a resonating direction in a laser cavity structure are provided on a second surface opposite to the first surface of the semiconductor substrate.