US 12,438,339 B2
External resonant laser module and method of manufacturing external resonant laser module
Atsushi Sugiyama, Hamamatsu (JP); and Tadataka Edamura, Hamamatsu (JP)
Assigned to Hamamatsu Photonics K.K., Hamamatsu (JP)
Filed by HAMAMATSU PHOTONICS K.K., Hamamatsu (JP)
Filed on Sep. 15, 2022, as Appl. No. 17/945,271.
Claims priority of application No. 2021-153099 (JP), filed on Sep. 21, 2021.
Prior Publication US 2023/0092813 A1, Mar. 23, 2023
Int. Cl. H01S 5/14 (2006.01); H01S 5/02326 (2021.01); H01S 5/34 (2006.01)
CPC H01S 5/141 (2013.01) [H01S 5/02326 (2021.01); H01S 5/3402 (2013.01)] 6 Claims
OG exemplary drawing
 
1. An external resonant laser module comprising:
a quantum cascade laser element;
a diffraction grating unit including a movable diffraction grating constituting an external resonator for the quantum cascade laser element;
a first lens holder disposed on a side opposite to a side where the movable diffraction grating is disposed with respect to the quantum cascade laser element and configured to hold a first lens for passing a first outgoing light from the quantum cascade laser element;
a second lens holder disposed between the quantum cascade laser element and the movable diffraction grating and configured to hold a second lens for passing a second outgoing light from the quantum cascade laser element and a light returned from the movable diffraction grating to the quantum cascade laser element; and
a mount member on which the quantum cascade laser element, the diffraction grating unit, the first lens holder, and the second lens holder are mounted,
wherein the mount member includes a first mounting portion, a second mounting portion, a third mounting portion, and a fourth mounting portion arranged in order from a side where the first lens holder is disposed toward a side where the diffraction grating unit is disposed along a facing direction in which the first lens holder and the second lens holder face each other,
the first lens holder is mounted on the first mounting portion,
the quantum cascade laser element is mounted on the second mounting portion,
the third mounting portion has a third mounting surface on which the second lens holder is mounted,
the fourth mounting portion has a fourth mounting surface on which the diffraction grating unit is mounted,
a protruding portion is provided on a surface of the diffraction grating unit facing the fourth mounting surface,
the fourth mounting portion is provided with a hole portion into which the protruding portion is inserted,
a length of the hole portion in the facing direction is longer than a length of the protruding portion in the facing direction so that the protruding portion can be slid in the facing direction with respect to the hole portion, and
a wall surface intersecting the facing direction and configured to position the diffraction grating unit is provided between the third mounting portion and the fourth mounting portion,
the diffraction grating unit includes a positioning surface facing the wall surface, and
the diffraction grating unit is fixed to the fourth mounting portion in a state where the protruding portion is inserted into the hole portion and the positioning surface is in surface contact with the wall surface.