Research And Application Of Semiconductor Laser Ignition Technology

With the development of laser technology and the improvement of safety requirements of initiating explosive devices in weapon system,as an advanced ignition technology,laser ignition technology has been widely concerned by the industry.Based on the semiconductor laser,a laser ignition system with single optical fiber structure is designed in this paper.Firstly,the basic requirements of laser ignition system are analyzed and the overall technical scheme of the system is determined,then,the main unit of the system,including the control module,the ignition laser driver module,the optical path detection module,the ignition time measurement module and the synchronous output module,are analyzed theoretically and the hardware circuit is designed,according to the work flow of the ignition system,the system software is designed and compiled,finally,the performance of each module in the system and the output of the whole system are tested.The details are as follows:(1)The structure of laser ignition system is analyzed and studied,and the overall design of the system is determined.By analyzing and comparing the advantages and disadvantages of single fiber and double fiber optical path structures,the optical path structure of the system is determined.According to the characteristics of each band semiconductor laser and the absorption spectrum of the igniting agent,the 980 nm and 1310 nm wavelength laser are selected as the igniting laser and detecting laser respectively from the perspective of the technological level and laser transmission loss of the fiber coupled laser module.(2)According to the overall design of the system,the hardware and software of the system are designed.The hardware design is mainly divided into two parts: system optical path design and control system hardware design,the optical path design part mainly designs the optical path structure based on the single fiber dual wavelength scheme,the hardware design of control system mainly includes the analysis and design of system power supply,main controller,laser driver,ignition time measurement,synchronous signal output,optical path detection,system security and other modules.The software design part is mainly based on the work flow of ignition system and MDK development tool,mainly including system initialization,laser temperature reading and monitoring,ignition laser power and pulse width setting,system optical path detection and other programs.(3)The quantitative detection of the optical path of the laser ignition system is realized by using the single fiber dual wavelength technology.The detection principle of the system optical path is analyzed and studied,and quantitative detection of the optical window reflectivity of the detonator is realized based on the optical path structure of the single fiber,the continuity of the optical path can be judged according to the measured reflectivity during the detection of the optical path of the ignition system,the photoelectric detection circuit is designed,and the detection of weak detection light signal is realized by optimizing the design.(4)The software and hardware cooperation test of each functional module is carried out,and the test results show that: the output current ripple of the laser driver circuit is small,no overshoot and high stability;the insertion loss and delay time of the optical switch in the security module meet the system design requirements;the accuracy of ignition time measurement module meets the expected requirements;the time difference between the output signal of the synchronous signal output module and the ignition signal decreases with the increase of the ignition power,and the maximum time difference meets the design requirements;the continuous operation of the system and multiple insertion and withdrawal of the detonator have little effect on the measurement of the reflectivity of the light window,and the measured reflectivity has little fluctuation;the accuracy of the laser power output and the stability of the central wavelength meet the expected requirements.The control system software has complete functions,simple operation and reliable operation.Each function module of the system runs stably under the control of the main controller,and finally realizes the basic functions of the laser ignition system,including optical path detection,system protection,laser ignition,etc.,and has high security and reliability.