| 摘要 |
PURPOSE:To eliminate the change in a light emitting mode or noise caused by the return light by arranging a prism so that light flux is not made vertically incident on an incident plane. CONSTITUTION:Light flux 1 made incident from a collimator lens 10 is made incident on a prism 2 at an angle theta1. When the incident light flux goes out from the prism 2, it has an angle of theta2 to the prism 2. Light reflected on a prism incident surface 3 is inclined at the angle DELTAtheta1 to the incident light. Similarly, the light flux to be reflected on a prism emitting plane 4 is inclined at an angle of DELTAtheta2 to the incident light. The prism 2 is arranged so that angles DELTAtheta1 and DELTAtheta2 not converge on a laser diode element 8 or a monitor element 9. Thus, since the reflected light flux is not converged to the collimator lens 10, the effect caused by the reflected light from the prism 2 on the laser is excluded. |
