超短激光脉冲测量研究进展

Research progress of ultra-short laser pulse characterization

超短激光脉冲作为产生阿秒激光与探索物质微观世界的重要工具,其时间特性的精确测量尤为重要。介绍了几种少周期激光脉冲的产生以及常用的表征技术,并将表征技术在广义上分为频域测量与时域测量两大类。在频域测量中,通过测量非线性过程产生的光谱信息来反演重构超短激光脉冲的包络及相位;在时域测量中,利用“超快门开关”直接对脉冲的光场信息进行采样,从而获取时间特性。两类技术在应用场景上各有侧重,频域测量因其装置简便快捷而被广泛应用在快速表征的实验场景中,而时域采样则因为可以直接获得光电场信息,常用于与光电场直接相关的超快物理实验。

As an essential tool for generating attosecond lasers and exploring the microcosmic world of materials,the precise measurement of the temporal profile of ultra-short laser pulses is significant.Several methods for the generation of few-cycle laser pulses and widely employed characterization techniques were reviewed.The characterization techniques were generally classified into two major categories:frequency domain and time domain measurement.In the frequency domain,the envelope and phase of ultra-short pulses were reconstructed through the measurement of the spectral information generated by nonlinear processes.In the time domain,the temporal profile of the pulse was obtained by directly sampling the optical field information using the ultrafast gate.These two types of techniques have distinct emphases in different application scenarios.The frequency domain measurement is widely employed in fast characterization experiments due to its simplicity and convenience,while the time domain sampling is commonly used in ultrafast physics experiments that are directly associated with the optical field,as it allows for the direct acquisition of photoelectric field information.