Abstract: In a symmetrically stable optical resonator, a first reference plane is set at an arbitrary position between the end face (102), opposing a partial reflector (2), and the neutral point (101) of a rod type solid state laser medium (1), and an aperture (5) having a diameter substantially equal to that of the rod type solid state laser medium (1) is arranged at a position optically symmetric to the reference plane with the partial reflector (2) as a neutral point using a relay lens (6) and a coupling lens (7) arranged between the aperture (5) and an optical fiber (8), the first reference plane is transfer-relayed onto the incident end face of the optical fiber (8), and the aperture (5) is transferred onto the coupling lens (7) through the relay lens (6).

Abstract: A laser oscillator includes a light condensing block having a through-hole for housing a laser medium, and an aperture for introducing excitation light from an excitation light source module into the through-hole; an end plate fixed to an end of the light condensing block, in which a cooling water channel for leading cooling water to the light condensing block and a cooling water channel for leading cooling water to the excitation light source module are formed; and a flow tube fixed and sealed by the end plate, for forming a cooling water passage for the laser medium; and an excitation light source module in which a cooling water channel, communicating with the water channel for the excitation light source module in the end plate, is formed for cooling its excitation light source.

Abstract: In a rod-type solid laser apparatus, a laser rod 1 is held by a rod holder 5, the rod holder 5 is held in a recessed portion 40 formed in an adjust ring 7, and the adjust ring 7 is mounted on a cavity container 4. The rod holder 5 is pressed against the cavity container 4 by the bottom surface of the recessed portion 40 of the adjust ring 7, and the diameter of the recessed portion 40 is set slightly larger than the outside diameter of the rod holder 5, whereby the rod holder 5 can be moved freely in the radial direction of the recessed portion 40 within the recessed portion 40. On the adjust ring 7, there are radially disposed two adjust screws 8a, 8b and a spring 9 which respectively extend from the side surfaces of the adjust ring 7 into the recessed portion 40 in such a manner that they are contacted with the rod holder 5. The rod holder is pressed and supported by three points, that is, the respective leading ends of the adjust screws 8a, 8b and spring 9.

Abstract: A laser oscillator includes a light condensing block having a through-hole for housing a laser medium, and an aperture for introducing excitation light from an excitation light source module into the through-hole; an end plate fixed to an end of the light condensing block, in which a cooling water channel for leading cooling water to the light condensing block and a cooling water channel for leading cooling water to the excitation light source module are formed; and a flow tube fixed and sealed by the end plate, for forming a cooling water passage for the laser medium; and an excitation light source module in which a cooling water channel, communicating with the water channel for the excitation light source module in the end plate, is formed for cooling its excitation light source.

Abstract: A solid-state laser apparatus comprises a plurality of solid-state materials each having an active solid-state medium and arranged in a row with a predetermined space on an optical axis of light incident thereon. An optical rotation material and an angle adjusting instrument for adjusting an angle between the optical rotation material and the optical axis of incident light are disposed in at least a space selected from among the plural spaces. The laser apparatus further comprises a laser optical system for extracting a laser beam emitted by the plural solid-state materials.