Intelligent Power Supply Design Of Laser Diode

In this paper, The pulse driven power is designed and it supply power for the laser diode. The design achieve automatic adjustment of the output optical power and temperature. The driven circuit of power is composed of the driven module of pulsed current and the automatic control module of temperature.The driven module of pulsed current is composed of current-source circuit and pulse generator and modulating circuit. In the module, Using a pulse signal as a control variable and high speed switching characteristic of field effect transistor, the pulse signal and the current signal are coupled by the modulating circuit. The circuit implements pulsed laser diode driver. In order to stabilize the output optical power of laser diode, the system use negative feedback circuit that is composed of the photodiode and current-voltage converter and voltage reference circuit and voltage comparator. The closed-loop control system can automatic control optical power of laser diode. In addition, Because of the laser diode there may be some of the security risk in the process of using. Design related circuit and has adopted effective measures to protect the security, So that the laser could be stable work.Automatic control unit of temperature use a combination of hardware and software. The design based on constant temperature control theory. The hardware circuit of system is composed of temperature sensor sampling and D/A converter and keyboard stetting and LED display circuit and alarm circuit. The software use digital PID control. Temperature control system realizes laser diode temperature's changes in the rapid response and automatic adjustment. Accuracy of the temperature control in the context and achieve the purpose of constant temperature control.