| 摘要 |
PURPOSE:To stabilize wave length even in a laser having large fluctuation of an output and wave length by constituting a monitor means of a convex lens, a separator lens which separates an image to be imaged by the convex lens in two and a detection means which outputs a prescribed signal, while two images of a laser beam passed through this separator lens are imaged. CONSTITUTION:A wave length monitor means 3 consists of a convex lens 12 having chromatic aberration, a separator lens 13 and a charge coupled device 14. A laser beam transmitted the convex lens 12 has different focal distances according to wave length. This image is separated into two images by the separator lens 13 so as to be imaged on the charge coupled device 14. An interval between the two images on this charge coupled device 14 is different with the wave length of the laser beam so that the wave length of the laser beam can be calculated by finding the interval by means of the charge coupled device 14. |
