| 摘要 |
PURPOSE:To reduce a reflected light quantity due to an incident angle and to improve the utilization efficiency of a laser beam by joining first and second prisms with different refractive indexes, and forming the angle of the joining boundary of both prisms so as to expand the width of a beam of light further when it enters from the first prism to the second prism. CONSTITUTION:The title device is constituted in such a way that light is refracted at the joining boundary 10a of both prisms by joining the first prism 11 and the second prism 12 with different refractive indexes, and the width of the beam of light of parallel rays can be expanded at the joining boundary 10a. Therefore, it is possible to lower the magnification of the width of the beam of light at the incident plane 11a of the first prism 11 corresponding to the magnification at the joining boundary 10a. By enabling the magnification at the incident plane 11a of the first prism 11 to lower, the incident angle theta1 can be reduced by that share. In such a way, it is possible to reduce the reflecting quantity of the light at the incident plane of the first prism 11, then, the utilization efficiency of the laser beam can be enhanced. |
