| 摘要 |
PURPOSE:To always maintain the coupling of a semiconductor laser and an optical fiber in the best state by controlling an output of a laser diode by making is output incident on the optical fiber, and applying a DC voltage proportional to its level to a stud provided with an ultrasonic vibrator. CONSTITUTION:Output light of a semiconductor laser 1, which has been condensed by a lens 2 and made incident on a fiber 3 is divided into two by a half mirror 10. One of them is made incident on the fiber 3 again, and the other is converted to an electric signal by a detecting amplifier 4, and inputted to a controlling circuit 6 after its high frequency component has been eliminated by a low-pass filter 5. By a DC voltage from the circuit 6, which has been applied to a voltage control moving plate 9, the thickness of a stud 8 provided with an ultrasonic vibrator is varied, and a direction in which the output light of the semiconductor laser installed on said stud is emitted is varied. In this way, by executing control so that an output of the detecting amplifier 4 becomes maximum, the best coupling state of the output light of the semiconductor laser 1 and the fiber 3 can be derived. |
