External resonance-type laser module

An external resonance-type laser module comprising:

• a quantum cascade laser including a laminated structure and emitting light from an end surface;
• a MEMS diffraction grating including a movable portion capable of swinging around a predetermined axis and a diffraction grating portion formed on the movable portion, wherein the MEMS diffraction grating diffracts and reflects the light emitted from the quantum cascade laser by the diffraction grating portion, and returns a part of the light to the quantum cascade laser;
• and
• a lens disposed between the quantum cascade laser and the MEMS diffraction grating, wherein
• the diffraction grating portion includes a plurality of lattice grooves arranged in a first direction and each of the plurality of lattice grooves extends in a second direction perpendicular to the first direction,
• the MEMS diffraction grating is disposed such that a normal line of the diffraction grating portion is inclined with respect to the end surface and the first direction is along a lamination direction of the laminated structure when viewed in a direction perpendicular to the end surface, and
• a length of the diffraction grating portion in the first direction exceeds a length of the diffraction grating portion in the second direction.