脉冲信噪比是高强度激光的一个重要技术参数，反映了激光系统的技术水平。由于高强度激光的重复频率很低甚至单次运行，必须开发实时的单次测量技术。当前，信噪比单次测量技术非常匮乏，技术难度远高于扫描测量方式。本课题组提出了可实现大窗口、高动态范围测量的技术方案，形成了系列创新技术，通过关键技术集成研制了实用化的测量样机。原理性验证实验考核了技术方案的可行性、可靠性和主要技术性能，已实现动态范围约为109、时间窗口50～100 ps和分辨率0.5～1 ps的信噪比单次测量，且在时间窗口内无测量引入的假信号。脉冲信噪比单次测量样机已成功应用于我国的拍瓦激光装置。

Pulse contrast is an important specification of high-intensity laser, reflecting the technical level of the laser system. As such lasers generally operate in a very low repetition rate and even in a single-shot mode, real-time single-shot measuring techniques are necessary for diagnosing pulse contrast. Compared with time-scanning measurement, the techniques for single-shot measurement are very deficient and more difficult. We present a new measuring scheme supporting high dynamic range and large temporal window simultaneously. Integrating the series of innovative technologies, we make a practical measuring prototype whose feasibility and reliability as well as the main performance have been examined by the proof-of-principle experiments. The pulse contrast can now been measured with high resolution and high fidelity at a dynamic range of about 109 within a temporal window of 50～100 ps. The invented measuring prototype has been applied successfully in the national petawatt laser system.