| 摘要 |
The directions of the generatrices of cylindrical lenses (11a, 11b) are orthogonal to the optical axis and orthogonal to each other. Thereby, an optical system using a combination of the cylindrical lenses (11a, 11b) is capable of performing the same optical action as a spherical lens does. Since each lens is a cylindrical lens, it has a feature that deviation of the optical axis will not occur even when it is moved in the direction of the generatrix. For example, in the case where damage to the lens becomes noticeable, the lens is moved in the direction of the generatrix (in the direction of arrow) by an unillustrated driving mechanism, e.g., a micrometer-equipped stage, to use the unused portion, thereby prolonging the life of the laser device. |
