| 摘要 |
PURPOSE:To realize output of highly directional laser light at a narrow band from one unit of laser by providing a partial reflecting mirror between a concave mirror and a convex mirror, by providing a diffraction grating to the opposite side of the partial reflecting mirror with the concave mirror between, and by making a hole which allows light to pass to a center of the concave mirror to form an unstable resonator by an excimer discharge tube. CONSTITUTION:An unstable resonator is constituted by providing an excimer discharge tube 1 with discharge electrodes 1a, 1b of excitation which are arranged inside a chamber whereto excimer gas is filled and with a concave mirror 2 and a convex mirror 3 in opposition at the both sides. A hole 2a is shaped to allow light to pass at the center of the concave mirror 2. A partial reflection mirror 4 is arranged between the excimer discharge tube 1 and the convex mirror 3, and a diffraction grating 5 is arranged to the opposite side of the partial reflecting mirror 4 with the concave mirror 2 between. The partial reflection mirror 4 and the diffraction grating 5 are arranged on a central axis of the unstable resonator to constitute a resonator. |
