| 摘要 |
<p>The external optical system of a laser can be simply structured at a low cost, and the entire system can be compact. A laser beam is reflected by a polarizing mirror (147) on one end side (10A) of a reflection-type resonator (10), and directed to a polarizing mirror (146) which is located diagonally below. The laser beam is reflected by a polarizing mirror (142), and directed to a polarizing mirror (141) which is located diagonally above. In other words, on the one end (10A), the polarizing mirror (141) and others are arranged to make the optical axis crosswise. The emitted laser beam is of linearly polarized light in the direction at an angle of 45 DEG to a horizontal plane as indicated by an arrow (100). In order to make this laser beam circularly polarized, only one 1/4 wavelength mirror is added. Therefore, it is possible to structure the external optical system simply. Also, since the optical axis can be crosswise on the reflecting sides, the systems can be arranged compactly as a whole. <IMAGE></p> |
