| 摘要 |
PURPOSE:To accurately monitor light output of a plurality of semiconductor laser elements having different wavelengths, and improve the reliability of a multibeam light head, by installing filters constituted of multilayer films on the light receiving surfaces of photodetectors. CONSTITUTION:A plurality of semiconductor laser elements 101, 102,... which are composed of InGaAlP and have different wavelengths are fixed on a copper stem 11 by using soldering metal. Through terminals 501, 502,... electric power is supplied to the laser elements 101, 102,..., which output laser light from the front surface and the rear surface. The laser lights 301, 302,... from the front surface are led out through a glass window 13, and used for writing/reading. The laser lights 401, 402,... from the rear surface are used for monitoring. The laser lights 401, 402,... of the laser elements 101, 102,... enter photodetectors 601, 602,... provided with filters constituted of multilayer films transmitting each oscillating light only, thereby leading out monitor output. |
