大功率半导体激光器的高精度脉冲电源设计

Design of high-precision pulse power supply for high-power semiconductor laser

为了满足大功率半导体激光器脉冲应用的实际需求,针对单脉冲内电流平顶下降问题和重复性情况下电流稳定性降低的问题,设计了一种多参数宽范围可调的高精度高稳定脉冲驱动电源。该电源以大功率场效应晶体管为核心,通过现场可编程门阵列产生的高精度时序波形来完成单脉冲内的上升沿调控和栅极控制电压补偿,通过微控制器结合电流采样的闭环控制方案实现重频运行下的电流高稳定输出。结果表明,在输出电流100 A、脉冲宽度400μs、重复频率1 kHz的最大功率输出驱动二极管负载时,驱动电流上升沿过冲幅度小于0.5%、单脉冲内电流衰减小于0.2%、重复率脉冲不稳定度小于0.1%;在同样输出条件下驱动半导体激光器,其在单脉冲内光功率过冲小于2%,重复光脉冲不稳定度小于0.2%。该研究有助于提高脉冲电源脉冲电流稳定性,对现有脉冲电源结构的改进具有一定的参考意义。

In order to meet the practical needs of high-power semiconductor laser pulse application, aiming at the problem of flat top current drop in a single pulse and the reduction of current stability in the case of repeatability, a high-precision and high stability pulse driving power supply with adjustable multi parameters and wide range was designed. The high-power field-effect transistor was took as the core of the power supply. The rising edge regulation and gate control voltage compensation in a single pulse can be obtianed through the high-precision timing waveform generated by the field-programmable gate array. The high and stable output of current under repeated frequency operation was realized through the closed-loop control scheme of microcontroller combined with current sampling. The results show that, when the output current, pulse width, and repetition rate of the loaded diode with maximum power output is respectively 100 A, 400 μs, and 1 kHz, the overshoot amplitude of the rising edge of the driving current is less than 0.5%, the current attenuation in a single pulse is less than 0.2%, and the instability of the repetition rate pulse is less than 0.1%. When the semiconductor laser is driven under the same output conditions, the optical power overshoot in a single pulse is less than 2%, and the instability of repeated optical pulses is less than 0.2%. This research is helpful to improve the stability of pulse current of pulse power supply, and has certain reference significance for the improvement of existing pulse power supply structure.