一种小型脉冲激光器能量和重复频率测量电路

A Small Laser Pulse Energy and Repetition Frequency Measurement Circuit

针对传统激光功率计无法实时检测的缺点,设计一种基于PIN光电二极管的小型激光脉冲能量和频率实时检测电路。在激光器输出窗口前端设置光学玻璃对激光输出进行透射和散射,利用PIN光电二极管探测激光散射信号并完成光电转换。微弱电信号经后续信号调理电路处理以外部中断方式触发单片机计时、计数,单片机同时采集调理电路的输出电压。系统最终实现了激光脉冲频率及能量的检测。测试结果表明:该系统的频率测量精度优于0.02%,能量测量精度优于1%,灵敏度优于0.8 V/mW,响应时间不大于3 ns。

A kind of circuit based on PIN photodiode is designed for measuring the frequency and power of laser pulse to solve the real-time detection problem of traditional laser power meter. The light intensity is decayed by the optical glass fixed in the front of the laser capsule. The photoelectric conversion is achieved by the PIN photodiode. After being processed through the conditioning circuit, the electricity signal is transferred to the microcontroller which calculates the pulse frequency in interrupt mode by counting the pulse amount and computes the pulse power by collecting the output voltage. This measuring system is able to monitor the state of high-power laser in real time. Results show that the frequency and power measurement precision of the circuit turns out to be less than 0.02% and 1% respectively. The sensitivity of this design is higher than 0.8 V/mW, while the response time is lower than 3 ns.