Abstract: A gas laser device includes an optical plate in an accommodating portion, a monitor module including a light entrance region and slidable on the optical plate, a positioning member on the optical plate for positioning the monitor module at a predetermined position on the optical plate, and a guide extending parallel to an optical axis of light traveling to the entrance region and guiding the monitor module toward the positioning member in the parallel direction. The monitor module includes a through-hole penetrating therethrough in the parallel direction and provided at a position deviating from the entrance region, slides on the optical plate to a predetermined region perpendicularly to the optical axis, then slides along the guide in the parallel direction toward the positioning member spaced apart from the predetermined region in the parallel direction, and is fixed in an internal space of the accommodating portion with a fixing member.

Abstract: An optical element angle adjustment device includes a first hinge that is an elastic hinge configured to connect a first plate and a second plate with each other, an optical element holding part attached to at least one of the first plate and the second plate, and a first adjusting screw configured to apply force in a direction of closing the first hinge to adjust a tilt angle of at least one of the first plate and the second plate. An end in an axis direction of the first adjusting screw is provided with a first press member configured to slidably abut on one of the first plate and the second plate. At least one of a first press member side abutting portion and a first hinge side abutting portion on which the first press member abuts has a curved surface in a curved surface shape.

Abstract: An optical element angle adjustment device includes a first hinge that is an elastic hinge configured to connect a first plate and a second plate with each other, an optical element holding part attached to at least one of the first plate and the second plate, and a first adjusting screw configured to apply force in a direction of closing the first hinge to adjust a tilt angle of at least one of the first plate and the second plate. An end in an axis direction of the first adjusting screw is provided with a first press member configured to slidably abut on one of the first plate and the second plate. At least one of a first press member side abutting portion and a first hinge side abutting portion on which the first press member abuts has a curved surface in a curved surface shape.