Narrow Pulse High-current Laser Excitation

The paper studies how a semiconductor laser works in the special condition satisfying the strict requirement. The writer has designed a circuit which can driver the semiconductor laser work in the given condition. It also details the history and the categories of laser and the laser driver especially the semiconductor laser. Based on the requirement of the very task, the whole process of design is described in this paper.There have been many huge changes of semiconductor laser since the first laser came to the world in 1962. Laser is looked as one of the most great inventions in the 21 century for it push the rapid development of other science and technology.But there is some distance between our country and other developed country in technology and fund. Now some transistors are used as the central unit of the semiconduct pulse laser driver which can produce tunable pulse from 50ns to 100ns. But my task need produce 30ns pulse, so the classic projects are not useful for me. According to the thinking and the real situation, the writer decide to use VMOStransistor to drive the semiconductor laser. Semiconductor laser is sensitive to the temperature, and the change of the temperature can alwaysinfluence the laser' s nature working. So the constant temperature technique of thermoelectric cooler is very important for the semiconductor laser. The writer spend a few time designing a temperature controller so that the laser can work stably, and the temperature of semiconductor pulse laser can be controlled within 20癈?癈.Finally, the writer have designed a semiconductor laser driver successfully, and the operational frequence is about 1HZ. 10HZ and 20HZ, and the pulse width is about 30ns and tunable, and the current is about3A.