US 12,424,816 B2
Semiconductor laser device
Naoki Kosaka, Tokyo (JP); Ayumi Fuchida, Tokyo (JP); and Naoki Nakamura, Tokyo (JP)
Assigned to Mitsubishi Electric Corporation, Tokyo (JP)
Appl. No. 17/636,313
Filed by Mitsubishi Electric Corporation, Tokyo (JP)
PCT Filed Nov. 28, 2019, PCT No. PCT/JP2019/046492
§ 371(c)(1), (2) Date Feb. 17, 2022,
PCT Pub. No. WO2021/106127, PCT Pub. Date Jun. 3, 2021.
Prior Publication US 2022/0285905 A1, Sep. 8, 2022
Int. Cl. H01S 5/02326 (2021.01); H01S 5/00 (2006.01); H01S 5/0231 (2021.01)
CPC H01S 5/0231 (2021.01) [H01S 5/0071 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A semiconductor laser device, comprising:
a stem having a mounting surface which is located to be opposite to and spaced apart from an emission port;
a semiconductor laser light source which is disposed so as to have beam components whose beam center is directed toward the mounting surface;
a reflective surface for reflecting laser light incident from the semiconductor laser light source toward the emission port; and
a secondary reflective surface for reflecting laser light incident from the semiconductor laser light source toward the emission port, which is continuous with an end portion of said reflective surface on its side nearer to the semiconductor laser light source;
wherein one of said reflective surface and said secondary reflective surface is constituted by a dielectric multi-layer film that is formed on a photodiode for measuring a light quantity of the laser light; and
wherein, in a plane perpendicular to the mounting surface and including the beam center, when an inclination angle of the beam center relative to the mounting surface is defined as α, an inclination angle β of said reflective surface is set to a value obtained by subtraction of a value that is less than α, from 45 degrees, while an inclination angle γ of said secondary reflective surface is set to a value obtained by subtraction of a value that is more than α, from 45 degrees.