| 摘要 |
PROBLEM TO BE SOLVED: To improve utility efficiency of discharge excitation energy and precision of wavelength selection by making an optical axis during actual laser oscillation coincide with an optical axis during alignment adjustment even if alignment adjustment of an optical system is performed in the absence of a laser chamber. SOLUTION: One boundary surface of first boundary surface 10 wherein a window is in contact with an outside of a laser chamber 3, and a second boundary surface 11 wherein the window is in contact with an inside of the laser chamber 3, is tilted by a specified angleαto the other boundary surface. When a specific refractive index of outside atmosphere of the laser chamber 3 is (na), a specific refractive index of a material constituting a window is (nw), a specific refractive index of laser gas inside a laser chamber is (nb), an optical incident angle from an outside of a laser chamber to the first boundary surface isθ1, and refraction angle in the first boundary surface isθ2, the tilt angleαis set to allow a relation of tanα=(nw.sinθ2-nb.sinθ1)/(nw.cosθ2-nb.cosθ1) to be satisfied. |
