| 摘要 |
PURPOSE:To reduce the hourly variation of the intensity distribution of the title device so as to maintain a uniform intensity distribution by providing an adjusting means which adjusts the intersecting angle of the polarizing direction of incident light with one side of the reflecting surface of the device. CONSTITUTION:Since the P-polarized light component Pa' on a surface (a) and S-polarized light component Sd' on a surface (d) increase when the polarizing direction of a laser oscillator changes counterclockwise by DELTAtheta due to thermal distortion, etc., the rays of light on surfaces (a) and (c) become weaker, but the rays of light on surfaces (b) and (d) become stronger. As a result, the intensity of diffracted light rays 16d increases in the X-axis direction and decreases in the Y-axis direction and differential operators 12a and 12b output positive voltage signals. A controller 13 rotates the guide cylinder 8 of the scope 1 and work table 14 counterclockwise by DELTAtheta by pushing an actuator 10 so as to return the intersecting angle to the original 45 deg.. Thus laser beam having a rectangular cross section suitable for working of surface modification, etc., and a uniform intensity distribution with less hourly variation can be obtained by fitting a beam uniformizing device using the scope to the laser oscillator. |
