小型化高稳定半导体激光驱动电路研究

Research on driving circuit for miniaturized high stable semiconductor laser

在小型化的可调谐半导体激光光谱测量应用中,高精度和高稳定度的激光驱动电路成为了制约光谱精确测量的主要因素之一。根据负载容量,分析和优化了线性电源的滤波电路参数,选择高稳定线性电源芯片LT3015和LT1086,并结合抗干扰布线规则,实现了12 h的稳定度为1.51×10^(-3)的线性电源。在此基础上,低功耗Cortex-M3内核单片机通过外部带参考基准的D/A芯片MCP4822实现温控芯片WTC3243和恒流驱动模块WLD3343的激光恒流恒温控制;外部电流驱动信号通过输入接口连接到电流控制端。不同温度条件下不同注入电流的短时光强实验和长时实验表明,其输出波数的差值分别为0.01个波数和0.014个波数,驱动电流与光强的线性相关系数大于0.9958、标准差小于7.60843×10^(-4)、Allan方差在5 s时小于2.597×10^(-4)。

In the measurement of miniaturized tunable semiconductor laser spectroscopy(TDLAS),high-precision and high-stability laser driving circuit is one of the key factors which guarantee the measurement accuracy.According to the load capacity,the filter circuit parameters of the linear power supply are analyzed and optimized.The high stable linear power chips of LT3015 and LT1086 are used for power management Combining with anti-interference routing rules,a linear power with high stability of 1.51×l0-3for 12 hours has been realized.Based on the power supply,the low power consumption Cortex-M3 microcontroller unit(MCU)is used as main controller.The temperature controller WTC3242 and the current controller WLD3343 are managed by the MCU by means of the D/A chip with inner voltage reference.The external current driving signal is connected to current controller by input interface of WLD3343.Finally,different currents driving experiments of laser output are conducted under different tempera-tures.The experimental results show that measurement errors of laser output for short-time and long-time are 0.01 wave number and 0.014 wave number,respectively.Meanwhile,linear correlation coefficient of driving current and light intensity is more than 0.9958;standard deviation is less than 7.60843×l0-4;Allan variance is less than 2.597×l0-4at 5 seconds.