Research And Design Of The Pulse Driver Of Semiconductor Laser

Semiconductor laser system as the core of optoelectronic devices,defense increasingly important role in the civil and national.Semiconductor laser has many other advantages of lasers can not match,so widely used in optical fiber communications,guidance,measurement,medical and information access and other fields.Application of semiconductor lasers such a broad,corresponding also its drive technology becoming more and more important.This paper mainly introduces the pulse drive semiconductor laser research.Thesis on the development of lasers and their applications,and is characterized by an analysis of the laser driver requirements. For the special requirements of this subject,a detailed analysis of the components of modules and the experimental results.At present,the way to improve the laser performance are mainly the study of new semiconductor laser technology to improve the performance of the device itself,or to improve the characteristics of laser-driven power.At present,both at home and abroad in the laser-driven research and has invested a great deal of manpower and material resources,but nowhere near the level of domestic and world's advanced level of science and technology.The study and design a new type of semiconductor laser is particularly important in the drive.This is designed to focus on the generation of pulse and switching current amplification.Narrow pulse is generated by the 555 timer circuit and the monostable multivibrator formed.In this paper constitutes selected chip SN74123 monostable multivibrator,the positive and negative edge of the work can trigger a typical propagation delay time is about 20ns,the edge of time to 15ns. SN74123 for 5V power supply,16-pin dual-may trigger Multivibrator Monostable, the output pulse width by the external resistor R and capacitor C decision.This article also analyzes the avalanche transistor,step recovery diode,such as high-speed electrical pulse produced several classical methods,the final choice is to switch current amplification by the VMOS achieved.VMOSFET is an ideal switching devices,through its closure,so that on-load and DC power supply connected to the formation of transient current pulse good.VMOSFET with high input impedance,low drive current,switching speed and current negative temperature coefficient,excellent thermal stability and security advantages of regional work.Therefore,it has a design consisting of a simple circuit,the system small in size,with automatic temperature compensation protection and so on.VMOS FET used here as a switching device to form a laser driver designed for the frequency of the pulse bandwidth can be adjusted drive circuit.The circuit has a pulse width,rise time,fall time is short,simple device. After simulation,the design can meet the technical indicators are operating frequency: 500～50kHz adjustable;pulse width:25ns or more adjustable;output current to achieve the maximum 5 amps.