Author Affiliations
Abstract
1 Chinese Academy of Sciences, Shanghai Institute of Optics and Fine Mechanics, State Key Laboratory of High Field Laser Physics, Shanghai, China
2 University of Chinese Academy of Sciences, Center of Materials Science and Optoelectronics Engineering, Beijing, China
3 Chinese Academy of Sciences, Shanghai Institute of Optics and Fine Mechanics, CAS Center for Excellence in Ultra-intense Laser Science, Shanghai, China
Temporal contrast (TC) is one of the most important parameters of an ultrahigh intense laser pulse. The third-order autocorrelator or cross correlator has been widely used in the past decades to characterize the TC of an ultraintense laser pulse. A novel and simple single-shot fourth-order autocorrelator (FOAC) to characterize the TC with higher time resolution and better pulse contrast fidelity in comparison to third-order correlators is proposed. The single-shot fourth-order autocorrelation consists of a frequency-degenerate four-wave mixing process and a sum-frequency mixing process. The proof-of-principle experiments show that a dynamic range of ～1011 compared with the noise level, a time resolution of ～160 fs, and a time window of 65 ps can successfully be obtained using the single-shot FOAC, which is to-date the highest dynamic range with simultaneously high time resolution for single-shot TC measurement. Furthermore, the TC of a laser pulse from a petawatt laser system is successfully measured in single shot with a dynamic range of about 2 × 1010 and simultaneously a time resolution of 160 fs.
ultrahigh intense laser single shot temporal contrast four-wave mixing fourth-order autocorrelator Advanced Photonics
2019, 1(5): 056001
北京大学 核物理与核技术国家重点实验室, 北京 100871
为了能够对强场飞秒激光进行单发实时准确的测量, 采用LabVIEW对单次自相关仪测量的数据进行实时分析处理, 设计了实时在线测量飞秒激光脉冲的测量系统。在数据分析时, 通过对图像处理区域的限制以及对图像数据积分极大地降低了信号的噪声, 提高了测量的准确性。利用自标定方法在线标定自相关仪, 实时获得激光脉冲宽度信息; 结合小尺寸像素CCD, 获得单像素3.6fs的精度; 并利用自主搭建的设备, 成功在线实时测量了中心波长800nm、脉宽约50fs的钛宝石激光脉冲。结果表明, 基于LabVIEW的单次相关仪能够实时测量飞秒脉冲, 且测量结果精度高、可靠性好。
超快光学 激光脉宽 单次自相关仪 实时测量 ultrafast optics pulse duration single-shot autocorrelator real-time measurement
中国工程物理研究院 流体物理研究所 光电子研究室, 四川 绵阳 621900
为了满足在高精度波分复用/时分复用光采样系统中, 采样光脉冲时间抖动低于100 fs的要求, 开发了一套基于自相关法测量时间延迟的系统。通过光纤耦合器连接一路参考光路将光脉冲在时域上进行“复制”, 并使初始光脉冲和“复制”光脉冲相关, 得到参考光路和被测光路的精确光程差, 进而固定参考光路并接入不同被测光路从而得到多路被测光路之间相对延时。实验结果表明, 利用自相关法测量脉冲时间间隔精度优于50 fs, 满足波分复用/时分复用光采样系统研究需要。
光采样 时间抖动 时间延迟 自相关仪 optical sampling time jitter time delay autocorrelator
中国工程物理研究院激光聚变研究中心,四川 绵阳 621900
针对非共轴三阶自相关法测试中对二倍频光束的要求，采用分步傅里叶变换方法对入射高斯光束，使用KDP晶体I类匹配的二倍频过程时间波形演变规律进行数值模拟，给出二倍频光束波形仍为高斯分布的入射基频光能量范围.不同二倍频效率下基频光与倍频光脉宽比值不同，所得的三阶自相关函数脉宽则不同，导致与脉冲形状有关的半高宽度换算因子不是固定值.分析结果对三阶自相关仪的参数设计和三阶自相关法测试中的误差分析有一定理论指导意义.
三阶自相关 倍频过程 高斯光束 时间脉冲波形 Third-order cross autocorrelator Second harmonic Gaussian pulses Temporal profile
1 天津大学精仪学院超快激光研究室,光电信息技术科学教育部重点实验室,天津,300072
2 香港科技大学物理系,香港九龙清水湾
3 俄克拉荷马州立大学电气与计算机工程系,激光与光子学研究中心,斯蒂尔沃特,OK,74078
报道一种ZnSSe双光子吸收光电二极管的新型飞秒自相关器,其工作波长覆盖400～800 nm的极宽光谱范围。用对紫外波长更为敏感的ZnMgS双光子吸收光电二极管,可延伸自相关器的工作波长至短于400 nm的紫外波段。
自相关器 双光子吸收 飞秒激光脉冲
Shanghai Institute of Optics & Fine Mechanics, The Chinese Academy of Sciences, Shanghai 201800
Chinese Journal of Lasers B
1998, 7(2): 142
