介绍了常见的强电磁干扰下的模拟信号传输方法，并改进了一种传输方案。首先，探测器一端将模拟信号转换为频率信号通过光纤发射器送出；其次，主控端接收光纤信号，在设置的读取时间内测量光信号的频率，计算获得相应的模拟量，代替传统上作频压转换后再作模数转换的做法，不仅节省了转换时间，提高了响应速度，而且可根据实际需求调整读取时间，从而获得不同的模拟量精度。在一台248 nm KrF准分子激光器上实际测试，实现了对变化较缓的气压信号的高精度在线监测，与传统方法对比更为准确，也可满足重复率0~90 Hz条件下激光脉冲能量检测信号的实时传输。通过计算皮尔森系数，该方案得到的采集值与原始信号趋于一致，满足应用需求。

Several analog signal transmission system under harsh electromagnetic interference environment was introduced, and a method of transmission was designed. Firstly, the analog signal was converted into a frequency signal through the detector and sent through the fiber transmitter. Secondly, the fiber signal was received and the frequency of the optical signal was measured within the configurable regularized time and then the analog signal was calculated instead of using the traditional method which converted analog signal to digital signal after frequency-to-voltage conversion. This system not only got the reduced total conversion time and improved response speed, but also can obtain different precision according to system requirements by adjusting converting time. Tested on a 248 nm KrF excimer laser, the system realized high-precision online monitoring of the slow-changing working gas pressure signal compared with traditional method, and then it also measured the fast-responsed energy signal of pulse laser up to 90 Hz well. By calculating the Pearson coefficient, the acquired value of the scheme tends to be consistent with the original signal to meet the application requirements.