Research On Narrow Pulsed Power Supply Of Semiconductor Laser

Semiconductor laser diode with its outstanding features,in so many high-technology areas such as military,medical,industrial production,optical fiber communications is playing a pivotal role.Semiconductor laser driven by pulse form is widely used in various fields because of its unique characteristics.The stability of the output current and the operating temperature of the semiconductor laser has a significant impact on the output performance.So it is of great importance to develop the pulsed power supply of semiconductor laserFirst of all,this thesis describes the basic working principle of the semiconductor laser and the main factors that affected the stable output of laser diode,and then puts forward requirements for the laser pulse drive power base.The driver system and protection circuit for semiconductor laser diode is designed based on the study of three kinds of pulse drive circuit and the characteristics of semiconductor laser diode.Because of semiconductor lasers need constant temperature for stable operation,this paper introduces the principle of constant temperature control of semiconductor laser.Constant temperature control system consists of NTC thermistor and semiconductor refrigerator.This paper completes circuit design for the temperature control system.The pulse drive circuit is composed of MOSFET,based on the application of negative feedback principle which can ensure stable driving current.MOSFET parallel can increase pulse drive current.The first simulation results of pulse driving circuit show that the rising edge of pulse current is too wide.After analyzing the reason of the rising edge too wide,a complementary symmetrical circuit is proposed to improve the switching speed of MOSFET.The second simulation results of improved pulse drive circuit show that the rising edge width reaches the target.After the pulse driving circuit and the semiconductor laser protection circuit are welded,the pulse driving circuit is tested.The experimental results show that the parameters meet the design requirements.The output current amplitude of pulse driving circuit can reach 150A;operating frequency can be 1~200Hz;pulse width can be 20?s~500?s;rising edge width of pulse current is less than 10?s.