| 摘要 |
PURPOSE:To reduce energy loss and to acquire arched beam by providing a dividing optical system which divides laser light which is output to an X-shape from an optical resonator provided to a position which divides a crossing angle into two. CONSTITUTION:Main stroke electrodes 13, 14 and other main stroke electrodes 15, 16 are arranged so that discharge directions thereof cross in an X-shape each other. Meanwhile, a prism 18 is provided in opposition to an output mirror 17 outside an excimer laser oscillation part 11, and the prism 18 is set in a position which divides a crossing angle wherein discharge direction crosses approximately into two. Beam 19 of an X-shaped pattern is output from the output mirror 17 and divided by the prism 18 provided to the outside thereof along (x-x) to form a pattern of half beams 20a, 20b. |
