| 摘要 |
PURPOSE:To adjust the position of a collimator lens in a short time with high precision by deciding on the position of the collimator lens so that laser light passed through the collimator lens is returned to a semiconductor laser by a reflecting member and monitor light is maximized. CONSTITUTION:Laser light emitted from a semiconductor laser 1 is passed through a collimator lens 2 and reflected by a pyramidal mirror 6 having a right-angled vertical angle to return to the semiconductor laser. Then, monitor light is detected through a monitor detector 5 and a peak detecting circuit 10. The semiconductor laser 1 is so set that its light emission point is closer to the lens side than to the focal point of the lens 2, and the laser 1 is moved finely away from the lens 2 along its optical axis through a movement control circuit 11 and a moving means 12; and a peak detecting circuit 10 detects the point where the output of the monitor light detector 5 is miximized and then stops the moving means 12. Thus, the position of the collimator lens is adjusted precisely in a short time. |
