Semiconductor laser device

A semiconductor laser device comprising:

• a semiconductor laser element;
• and
• a package that accommodates the semiconductor laser element,
• wherein the package includes:
• a bottom wall;
• a side wall standing on the bottom wall and being formed in an annular shape to surround a region in which the semiconductor laser element is accommodated, when viewed in a direction perpendicular to the bottom wall;
• and
• a top wall that closes an opening on an opposite side of the side wall from a bottom wall side,
• a light-emitting window through which laser light emitted from the semiconductor laser element passes is provided on the side wall,
• the light-emitting window includes:
• a first hole portion that extends along an optical axis direction along an optical axis of the laser light;
• a second hole portion that extends along the optical axis direction, and that includes the first hole portion and is larger than the first hole portion when viewed in the optical axis direction;
• a counterbore surface having an annular shape that connects the first hole portion and the second hole portion and that extends along a plane intersecting the optical axis direction;
• and
• a window member disposed inside the second hole portion,
• a surface of the window member facing the counterbore surface includes:
• a first region which includes a central portion of the surface of the window member facing the counterbore surface and in which a first anti-reflection film is provided;
• and
• a second region metallized and formed in an annular shape to be separated from the first region and to surround the first region, and
• the second region is joined to the counterbore surface through a solder member.