摘要
分布反馈(DFB)激光器作为可调谐半导体激光吸收光谱(TDLAS)技术的常用光源之一,在实际应用中应当同时对驱动电流和温度进行控制,以减小出光质量对气体浓度检测结果的影响。为了解决上述问题,文中设计一种高精度激光器驱动电路。由STM32F103RCT6控制AD9834和DAC8560分别产生正弦波和锯齿波信号,对两个信号输入至OP27GS构成的信号叠加电路进行叠加后,输出至由OP27GS、AD8065和IRF520场效应管组成的具有限流功能的压控恒流源电路,将电压信号转变为激光器的驱动电流;同时采用MAX1978温控芯片对激光器进行温度控制。实际测试结果表明,压控恒流源输出电流的最大误差为0.1%,DFB激光器的温度稳定度为0.072%,温度控制精度优于0.01℃。使用3000 ppm的甲烷标准气体进行吸收测试,通过示波器检测光电探测器和锁相放大器的输出波形,可得到稳定的吸收峰和二次谐波,说明所设计电路满足TDLAS检测技术对于DFB激光器驱动的要求。
As one of the commonly used light sources for tunable diode laser absorption spectroscopy(TDLAS)technology,the distributed feedback(DFB)laser should be used in practice to control both the drive current and the temperature to reduce the influence of the quality of the light output on the gas concentration measurement results.In order to solve above problems,a high‐precision laser driver circuit is designed.The STM32F103RCT6 is used to control the AD9834 and DAC8560 to generate sine wave and sawtooth wave signals respectively,and the two signals are input to the signal superposition circuit composed of OP27GS for superposition,and then output to the voltage controlled constant current source circuit with current limiting function composed of OP27GS,AD8065 and IRF520 field effect tube to transform the voltage signal into the laser drive current.At the same time,the MAX1978 temperature control chip is used to control the temperature of the laser.The actual testing results show that the maximum error of the voltage controlled constant current source output current is 0.1%,the temperature stability of the DFB laser is 0.072%,and the temperature control accuracy is better than 0.01℃.Using 3000 ppm methane standard gas for absorption test,stable absorption peaks and second harmonics can be obtained by detecting the output waveforms of the photodetector and lock‐in amplifier by means of oscilloscope,indicating that the designed circuit meets the requirements of TDLAS detection technology for driving DFB lasers.
作者
徐鹏飞
李炜楠
陈红岩
叶有祥
XU Pengfei;LI Weinan;CHEN Hongyan;YE Youxiang(School of Electrical and Mechanical Engineering,China Jiliang University,Hangzhou 310018,China;College of Modern Science and Technology,China Jiliang University,Yiwu 322000,China)
出处
《现代电子技术》
北大核心
2024年第2期89-94,共6页
Modern Electronics Technique
基金
浙江省基础公益研究计划(LGF21E040005)。
关键词
气体检测
TDLAS
DFB激光器
驱动电路
压控恒流源
温度控制
gas detection
TDLAS
DFB laser
drive circuits
voltage controlled constant current sources
temperature control
