| 摘要 |
<p>PURPOSE:To obtain an optical semiconductor device with which the far-sight image characteristics of a signal beam can be improved by a method wherein a light emitting device and a spherical lens provided on the side to which the monitor beam of the light emitting device is emitted are housed in a container. CONSTITUTION:A monitor beam 8 emitted from a laser diode 2 and applied to a spherical lens 6 is condensed by the lens 6 and formed into a thin beam and applied to the light detecting plane 3a of a photodetector 3 and focused as a small light spot. As the reflected beam 8a of the focused monitor beam 8 is close to a reflected light from a point source, it is scattered radially to a wide range. Therefore, the application of the reflected beam 8a from the surface of the light detecting plane 3a to the light emitting layer 2b of the laser diode 2 is suppressed to be little. Moreover, as the main components of the monitor beam 8 are applied to the spherical surface of the lens 6 almost vertically, the reflected beam 8a of the monitor beam 8 reflected by the spherical surface of the lens 6 is hardly applied to the light emitting layer 2b. Therefore, the signal beam of the laser diode 2 can have excellent far-sight image characteristics.</p> |
