为了满足中红外波长调制光谱技术中室温连续中红外量子级联激光器的驱动要求, 设计并研制了一种量子级联激光器驱动电源系统.首先, 设计了直接数字合成模块来产生直流、锯齿波和正弦波的叠加驱动信号以调谐激光器的电流, 进而调制其输出波长；其次, 设计了高速(约40 ns)过流保护电路, 配合电压深度负反馈原理, 保证激光器工作的可靠性, 提高激光器电流的稳定度；再次, 将比例-积分-微分软件算法与温度模拟控制电路相结合, 在简化电路结构的同时, 有效地控制和稳定激光器的温度, 防止因温度变化造成激光器输出波长的漂移和发光功率的波动.利用该驱动电源系统对中科院半导体所研制的中心波长为4.76 μm的量子级联激光器做驱动测试,结果表明:驱动电源系统电流调节的线性度为0.0068%, 驱动电源的长期(240 h)电流稳定度为4.99×10-5, 量子级联激光器的光强稳定度为5.07×10-4, 控温稳定性为0.01℃, 温度稳定时间为17 s;当量子级联激光器的驱动电流为330 mA, 温度为21℃时, 在240h内峰值波长的漂移为±0.02nm.

In order to satisfy the capability of driving room-temperature continuous mid-infrared quantum cascade laser based on the mid-infrared wavelength modulation spectroscopy, a novel quantum cascade laser driver was designed and implemented under experimental evaluation. Firstly, a direct-current, a repetitive ramp and a sinusoid were generated to tune drive current and to produce a modulation in the wavelength of quantum cascade lasers via a function generation module. Secondly, a comprehensive and high-speed (the response time is about 40 ns) over-current protective circuit was developed in conjunction with the deep voltage negative-feedback theory, which guaranteed the laser operation reliability and improved the stability of drive current. Again, a complete temperature analog control circuit and a proportional-integral-differential software algorithm were combined to simplify the circuit structure and to control and stabilize the laser temperature effectively, which prevented the drift of the laser output wavelength and the fluctuations of the emission power caused by the temperature change. Via the use of the driver, driving tests were carried out on a mid-infrared quantum cascade laser with center wavelength at 4.76 μm, which was fabricated by institute of semiconductors, Chinese Academy of Sciences. Experimental results demonstrated that current regulation linearity of the drive power system is 0.0068%, the stability of drive current during long time (240 h) is 4.99×10-5, the stability of light power is 5.07×10-4, the temperature stability is 0.01℃ and the stable control process is 17s,the drift of wavelength at peak within 240 h is ±0.02 nm when drive current of the quantum cascade lasers is 330 mA and the temperature is 21℃.