US 12,327,976 B2
External resonance-type laser module
Tadataka Edamura, Hamamatsu (JP); Atsushi Sugiyama, Hamamatsu (JP); and Naota Akikusa, Hamamatsu (JP)
Assigned to HAMAMATSU PHOTONICS K.K., Hamamatsu (JP)
Filed by HAMAMATSU PHOTONICS K.K., Hamamatsu (JP)
Filed on Feb. 18, 2022, as Appl. No. 17/675,166.
Claims priority of application No. 2021-027525 (JP), filed on Feb. 24, 2021.
Prior Publication US 2022/0271491 A1, Aug. 25, 2022
Int. Cl. H01S 3/08 (2023.01); H01S 3/1055 (2006.01); H01S 5/02253 (2021.01); H01S 5/14 (2006.01); H01S 5/34 (2006.01)
CPC H01S 3/08059 (2013.01) [H01S 3/1055 (2013.01); H01S 5/02253 (2021.01); H01S 5/141 (2013.01); H01S 5/3401 (2013.01); H01S 5/3402 (2013.01)] 8 Claims
OG exemplary drawing
 
1. An external resonance-type laser module comprising:
a quantum cascade laser;
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 light emitted from the quantum cascade laser by the diffraction grating portion, and returns a part of the light to the quantum cascade laser;
a lens disposed between the quantum cascade laser and the MEMS diffraction grating;
a magnet disposed on a side opposite to the quantum cascade laser with respect to the MEMS diffraction grating; and
a yoke forming a magnetic circuit together with the magnet, wherein
the movable portion is formed in a plate shape, the MEMS diffraction grating includes a support portion and a connecting portion connecting the movable portion to the support portion on the axis such that the movable portion is capable of swinging around the axis, the movable portion is capable of vibrating as a single degree-of-freedom vibration system,
the MEMS diffraction grating further includes a coil formed in the movable portion and on which a magnetic force of the magnet acts, the coil includes a pair of coils respectively disposed on one side and the other side with respect to the axis when viewed in a normal direction parallel to a normal line of the diffraction grating portion, and each of the pair of coils includes an inside part extending along the axis, and
a recess portion is formed in a surface of the magnet on a side of the MEMS diffraction grating and at least a part of the recess portion overlaps the inside part of each of the pair of coils when viewed in the normal direction.