提出一种基于全光纤光谱干涉的多路超短脉冲大动态范围时间同步单次测量方法,弥补了非线性相关法测量同步状态时测量范围小和示波器测量时分辨率差的不足,解决了同步测量中空间光路的复杂性和单次实时测量的难题。首先对多路光纤阵列干涉测量进行仿真计算,然后设计四路脉冲传输的光路并在实验中验证多路同步单次测量方法的可行性,最后详细分析测量误差的来源和影响。该测量方法的最小同步时间精度为5.3 fs,测量范围为1.055~14.751 ps,与仿真结果有较好的一致性。该测量方法具有光纤链路易于集成、光谱干涉数据处理速度快、测量信号能量需求低等优势,在多路超短脉冲激光相干合束系统中有重要应用前景。

太赫兹单次测量技术可以对一些超快不可逆过程进行快速测量,在蛋白质变性、核爆模拟分析等领域具有广阔的应用前景。从飞秒激光放大器发出的光脉冲分成两束并分别经过两块光栅产生波前倾斜,一束作为抽运光激发铌酸锂晶体,基于光整流效应产生高功率太赫兹波;另一束作为探测光,采用正交平衡探测法探测。利用该光路产生太赫兹脉冲并对其进行单次测量,系统的时间窗口为16.8 ps,频谱范围覆盖0.1~1.6 THz。

An all-fiber Faraday rotator isolation rate measurement system is designed and realized. The system has tremendous advantage for large aperture Faraday isolator on-line measurement due to its flexible alignment and more compaction. Employing the method of relative transmission measurement and transmissions contrasting between static and operating states, single-shot isolation-rate measurement is achieved. The available measurement range larger than 33 dB is demonstrated experimentally. And the potential to get measurement range larger than 50 dB by adjusting the coupling rate of the fiber couplers is affirmed. Measurement accuracy of 2.2%of PV value is achieved even while keeping the input pulse energy and polarization in random vibration, which illustrates that the influence of the input pulse energy and polarization vibration on the measurement accuracy is eliminated.

An all-fiber Faraday rotator isolation rate measurement system is designed and realized. The system has tremendous advantage for large aperture Faraday isolator on-line measurement due to its flexible alignment and more compaction. Employing the method of relative transmission measurement and transmissions contrasting between static and operating states, single-shot isolation-rate measurement is achieved. The available measurement range larger than 33 dB is demonstrated experimentally. And the potential to get measurement range larger than 50 dB by adjusting the coupling rate of the fiber couplers is affirmed. Measurement accuracy of 2.2%of PV value is achieved even while keeping the input pulse energy and polarization in random vibration, which illustrates that the influence of the input pulse energy and polarization vibration on the measurement accuracy is eliminated.

太赫兹脉冲单次测量技术对于不可逆或者单次超快过程的太赫兹光谱研究具有重要意义。为了实现无畸变的高频率分辨率的太赫兹脉冲单次探测，利用光栅产生了一束具有倾斜前沿的飞秒探测脉冲，并利用该探测脉冲实现了对太赫兹脉冲时域电场波形的单次测量，测量时间范围达到20 ps，频谱覆盖0.1 THz~2.5 THz 范围。且测量的结果与使用传统电光采样方法测量的结果相符合。对于基于光栅产生倾斜脉冲前沿的太赫兹脉冲单次测量方法进行了建模分析，获得了光栅和光学元件参数的选取，以及光路设计等指导性结论。

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。

利用瞬态光栅衍射法研制了一台单次频率分辨光学开关激光参数测量仪，可以对脉宽范围在10 ps以内的紫外超短脉冲激光进行单次测量。利用该仪器对重复频率为10 Hz的放电泵浦和单次运行的电子束泵浦KrF准分子激光器的输出脉冲分别进行了单次测量，结果表明：对于放电泵浦，当系统工作在零啁啾附近时，脉冲波形和光谱分布较规则，相位分布起伏较小，当系统偏离零啁啾状态时，脉冲波形和光谱分布不再规则，并且相位分布为抛物线结构；对于单次运行的电子束泵浦，脉冲波形具有多峰结构，光谱具有复杂的调制，脉宽约为2 ps，带宽约为1.3 nm，相位分布为抛物线结构。