| 摘要 |
PURPOSE:To stabilize light pulse amplitude by installing a transistor which is newly added to a pulse modulation circuit for a laser diode and functions as a temperature compensating circuit. CONSTITUTION:The collector of the first transistor 2 which constitutes a pulse modulation circuit is connected with a laser diode 1, and this connection point is connected with a bias current supply terminal 6. The base of the transistor 2 is connected with a modulation pulse voltage supply terminal 7, its emitter is connected with the emitter of the second transistor 3, its collector is connected with the diode 1 and its base is connected with a switching threshold voltage supply terminal 8. After that, a DC power source 5 is connected between the connection point of the transistors 2 and 3 and the diode 1 via a resistor 10, wherein a transistor 9 which is a temperature compensating circuit connected with a DC voltage supply terminal 11 is installed between the transistor connection point and the resistor 10. By so doing, a temperature characteristic is given to a pulse modulation current source. |
