分析了原有超短脉冲激光调制系统驱动器存在的不足,提出了改进方案。研制的调制系统驱动器运用声光调制技术,采用了FPGA器件,代替了分立元件;在芯片内实现高频信号的产生,并且完成了射频信号分频、鉴频和鉴相以及信号调制的功能,解决了高频信号传输的难题。研制的超短脉冲激光调制系统驱动器能够输出4 M,800 k,400 k,80 k,40 k,8 k,4 k,800,400 Hz等不同重复频率的脉冲信号,输出功率达到瓦级,满足了声光布拉格池的要求。匹配网络的加入使声光换能器充分吸收腔倒空驱动器输出的功率,增加衍射效率。激光脉冲调制系统已应用在皮秒时间相关单光子计数光谱仪系统中,在实际应用中取得了理想的效果。

The improving scheme is proposed, after analysing the defect of the original driver circuit of ultra-short pulse laser modulation. The driver system developed bases on the acousto-optic modulation, and FPGA is used to replace the isolated components. The unit that produces the high frequency signal is designed in the chip, and the frequency and phase discrimination and signal modulation are accomplished, so the difficulty of the RF signal transmission is resolved. The cavity dumper driver designed can make the acousto-optic cell output the different repeated rate laser pulse signals whose rates are 4 M, 800 k, 400 k, 80 k, 40 k, 8 k, 4 k, 800, 400 Hz,etc. The power of the output signal is wattage level required by the acousto-optic (Bragg) cell. The matching net has been used in the system, so the power that the driver exports can be absorbed fully by the acousto-optic energy convertor. The laser pulse modulation system developed have used in the pico-second time-correlated single photon counting spectrometer, and the result is perfect in the application.