半导体激光器亚微安级低噪驱动电路设计与稳定性分析

Design and Stability Analysis of Sub-Microampere Low-Noise Drive Circuit for Semiconductor Lasers

为满足精密测量等领域对半导体激光器的波长稳定性、相位噪声等指标的严苛要求,提出基于系统传递函数理论推导论证与仿真验证相结合的分析方法,并由此设计改进了一款半导体激光器的高稳低噪恒定电流驱动电路。绘制了电流驱动电路的交流小信号模型和交流通路,对电路参数和系统稳定性的关系进行了理论分析,并引入噪声抑制网络对电路进行改进,通过Tina-TI仿真验证了改善后的驱动电路在2 MHz带宽内的噪声抑制能力和稳定性。实验结果表明,恒流驱动电路在3 KHz~2 MHz宽带内交流噪声有效值为224 nA,连续驱动电流2.5 h稳定度优于1.904×10^(-6),1 h光功率积分时间1 s时的稳定度为1.177×10^(-5)。仿真与实验基本相符,驱动电路具有较高的稳定性和噪声抑制能力,同时,该分析方法对半导体激光器的超低噪声的驱动电路设计和优化具有普遍的理论指导意义。

To satisfy the strict requirements of semiconductor lasers in terms of wavelength stability,phase noise,and other indicators in precision measurements and similar applications,an analysis method based on the combination of system transfer function theory derivation analysis and simulation verification is proposed.We designed a semiconductor laser diode drive circuit with a smaller wavelength drift and ultralow noise.For an alternating current smallsignal model and alternating current path,we theoretically analyzed the correlation between the circuit parameters and system stability.The circuit design was optimized by introducing a noisesuppression network.Using TinaTI simulations,the drive circuit loop noise is effectively suppressed,and the system stability improves to a bandwidth below 2 MHz.Experimental results reveal that the effective value of alternating current noise is approximately 224 nA and 1.9×10−6 for the direct current ripple between 3 kHz and 2 MHz in 2.5 h.When the 1 h optical power integration time is 1 s,the stability is 1.177×10−5.These results verify the theoretical model and simulation analysis.Notably,this approach provides a universal guideline for analyzing and designing ultralow noise current drivers for semiconductor laser diodes.