| 摘要 |
PURPOSE:To sheet out stray light to eliminate malfunctions due to stray light by making the surface on the other side of an optical separator convex and at the same time providing an optical attenuation means in the part of a housing set opposite to said side face of the optical separator. CONSTITUTION:It is supposed that the partial light A of the light S received from a semiconductor laser 10 is reflected by a spectral face 21D of a half-prism 21 as shown by the dotted lines. Thus the light A is condenced on a face 21E of the other side of the prism 21 and led outside a housing 3 through a small hole 22 of the housing 3. Therefore the light A is never turned into the stray light. Furthermore it is also possible to prevent the light A from reaching the prism 21 again by changing the traveling direction of the light A by means of a mirror, etc. Here the setting angle of the mirror must be controlled so that the prism 21 does not exist on the optical axis of the mirror. For this purpose, an optical attenuation means is formed with a mirror, etc. |
