The Design And Facture Of Semiconductor Laser Pulse Driver

As the development of semiconductor laser,it has its own good characters.This made it enter other fields which is difficult for other lasers.It has been the core of the semiconductor optoelectronic devices.The semiconductor laser has many good characteristics such as high transform efficiency, small size, light weight,high reliability,direct modulation and easiness to be integrated with some other semiconductor devices.So it has been applied in many fields like industry,mining,Construction, basic research, such as IAF also has a wide range of applications,the semiconductor laser has been applied in every field. For the applications of LD,because it has slight heat effect and low occupancy ratio, the pulse driver is the ideal driver. And the LD working in the short pulse not only can allow the pass of the high pulse current which is much higher than the constant driver current,but also does not need to give out heat. Laser for laser actuators vary,each must have its laser power line, as the working methods of different lasers,pulsed in the work of the state, there are also continuous state work, and therefore also the corresponding laser power Pulse-divided into two types,and continuous.Narrow large current pulse laser-driven research with theoretical significance. The author of the narrow access to a lot of high-current pulsed laser-driven aspects of literature and publications, found that domestic research in this area and the Western developed countries still have a big gap. United States semiconductor lasers some professional firms,the incentive for them to produce now has been modularized, and the product reliability and stability are good.Western developed countries laser actuators in each invest a lot of manpower and material resources, compared to the domestic input in this respect is a lot less, a study in this regard is necessary.Narrow large current pulse of the laser-driven research also has practical significance.With our country's strong social progress and economic growth,an increasing number of industries, laser doors to work for it.For example,in the military field,laser-guided laser weapons.These are now urgently needed to develop our country,and they are inseparable from the laser.More in the civil context, many of the laser range finder, laser drilling machines are also inseparable from the laser.Therefore, good research and design a laser actuators have very important practical significance.In this paper,in the understanding of the working principle of semiconductor lasers and various driving mode, in accordance with the design requirements,we finish every module.we also also realized the additional pulse voltage output.After the realization of the main function,we add temperature control, interference and other necessary auxiliary circuit.The focus of this design is a part of the trigger pulse,pulse generation and power amplifier parts.Triggered in part by the multi-pulse harmonic oscillator,monostable multivibrator and switch components.Which Multivibrator by 555 timers and several appropriate resistive and capacitive components of the composition. RC oscillator is commonly used semiconductor devices rely on the amplification and storage elements of the selected frequency to generate self-excited oscillation.Consisting of more than 555 timer,and its different harmonic oscillator,it is relying on the role of switching semiconductor devices and storage elements of the charge-discharge to generate self-excited oscillation.Timer 555 is a multi-purpose digital - mixed analog integrated circuits,with easy-to-use, flexible features, and extensive application of stable performance.As long as its external accompanied by several appropriate resistive and capacitive components,can be very convenient to a pulse generator and changes circuit.Monostable multivibrator output with a steady, when the foreign trigger pulse,it can go from the steady suspense steady and maintain for a period of time and then return to the steady state.This depends on the length of circuit parameters,by changing the circuit parameters of the output pulse width can be changed.This paper will use 74 LS123 integrated monostable multivibrator and change its external R and C can be changed on the output pulse width.In this output can not meet the requirements of the rate case, the switch of choice, do not change the width of the circumstances, the magnitude magnified.In the analysis and comparison of the step recovery diodes,VMOS of high-speed devices such as a high-speed pulse theoretical methods,the final choice of using avalanche to achieve narrow pulse and current amplification part,we said that two-and the avalanche of pre-class avalanche. When the avalanche collector voltage is high enough, the space-charge collector junction area of low pressure over the electric field intensity at the application many times.Collector Junction entered the carrier was strong electric field to accelerate and has great energy,and their collision lattice creates new electronic - hole right. New electronics, holes were also strong electric field to accelerate and repeat the process.Therefore, the flow's collector current "avalanche" of rapid growth,which is double the transistor avalanche phenomenon.It should be stated that, avalanches avalanche transistors in the process of the instantaneous power consumption great, but because avalanche very short duration (a few ns), with the longer term work, it is not the average power consumption tubes generally choose to repeat in the frequency of 100 kHz following more appropriate. In addition, because current avalanche great. Collector high voltage in the circuit debugging attention should be paid to wiring reasonable, only to reduce and eliminate the impact of distribution parameters can be satisfied with the performance. If a single avalanche of the current pulse amplitude is not big enough, a number of parallel, but also need to consider conduction problems. Through two avalanches had a pulse rate of more than 1 ns-A pulse current, in this middle also had a 2 ns wide, 7 A peak voltage pulse.In the realization of basic design requirements, in order to ensure that power laser diode driver stability, increased perimeter protection and temperature control necessary part. Surge circuit to prevent interference main impact of a sudden surge of the moment, pulse, the semiconductor laser transient overvoltage easily bear the pn junction breakdown in the transient overvoltage positive generated by the current optical power can cleavage of injury. The main source of interference is to share power grid, the power grid is a system, is a serious source of interference. Circuit interference or suppression of the main tasks of the grid system interference. Available in a number of heating and cooling chips, chosen by thermistor as a temperature sensor, the temperature corresponding voltage value as a reference voltage, by comparison, the output value by a margin of two values, which can be controlled through TEC's current direction, and this can be controlled TEC heating cooling process, so as to achieve a constant temperature control, such as temperature control circuit of auxiliary circuit in the accuracy requirements are not too high, there relatively large error, For further improved, and PID can join similar circuit to adjust the parameters, so as to achieve the purpose of a fine-tuning. How will these organic combination of a practical power, single-chip microcomputer will consider combining pulse frequency, pulse width, and other useful information on the LCD display screen. These matters need to be on the next step in the direction.