基于“时频变换”的主动超快成像方法(特邀)  

Active Ultrafast Imaging Based on Time-Frequency Transform(Invited)

作　　者：陆宇 陈烽[1] Lu Yu;Chen Feng(State Key Laboratory for Manufacturing System Engineering,Shaanxi Key Laboratory of Photonics Technology for Information,School of Electronic Science and Engineering,Xi’an Jiaotong University,Xi’an 710049,Shaanxi,China)

机构地区：[1]精密微纳制造技术全国重点实验室,陕西省信息光子技术重点实验室,西安交通大学电子科学与工程学院,陕西西安710049

出　　处：《光学学报》2024年第17期90-106,共17页Acta Optica Sinica

基　　金：国家自然科学基金(12127806,62175195)。

摘　　要：针对诸多基础科学和工程应用领域,发展飞秒到纳秒时间尺度的超快成像方法具有非常重大的理论与工程意义。作为一类当前被广泛研究的超快成像方法,基于“时频变换”的超快成像方法在成像的时间分辨率、单次曝光获得的图像帧数、可观测的时间范围等方面都具有独特的优势。本文首先介绍“时频变换”超快成像的基本原理,并从“时频变换”超快成像的两个主要组成部分:“时频变换”观测脉冲的产生和时间-光谱图像序列的恢复入手,对当前“时频变换”超快成像新方法进行系统性介绍。将围绕超快成像的时间与空间特性,对不同“时频变换”超快成像方法的优势与特点进行探讨,并展望“时频变换”超快成像方法在未来的发展方向。Significance With the development of fundamental physics,chemistry,materials science,and energy engineering,many processes that occur on the nanosecond(ns,10-9 s)to femtosecond(fs,10-15 s)time scales,known as ultrafast processes,have become crucial topics in research in related fields.Examples include ultrafast plasma dynamics and X-ray emission dynamics in nuclear fusion investigations.However,observing these ultrafast processes,which aim to record transient dynamics including information from at least two spatial dimensions,remains a significant technical challenge.Current methods for observing ultrafast processes,namely,ultrafast imaging techniques,can be divided into two categories:passive imaging techniques and active imaging techniques.Passive imaging techniques suffer from electronic bottlenecks such as the confinement of carrier movement speed,parasitic capacitance and inductance,and spatial dispersion of electrons,severely restricting their spatial and temporal resolution.Active ultrafast imaging techniques use illumination pulses to observe ultrafast processes,capturing light signals from the observation pulses themselves.This approach overcomes the limitations of electronic bottlenecks on imaging speed and quality in ultrafast imaging technology.With the rapid development of ultrashort pulse generation techniques,ultrafast imaging based on pump-probe,the most commonly applied active imaging technique,can achieve temporal resolutions as fine as a few femtoseconds and spatial resolutions down to sub-micrometer scales.However,pump-probe techniques can only capture a single snapshot of the observed ultrafast process in each observation.To capture the entire ultrafast process,it is necessary to continuously repeat the experiment.The delay between the pump pulse and the probe pulse(observation pulse)must be adjusted accordingly to capture different transient slices.Consequently,pump-probe techniques are not suitable for recording non-repeatable ultrafast processes with significant randomness.In recent years,

关 键 词：超快光学 超快成像 时频变换 飞秒激光 时间-光谱图像序列 

分 类 号：O436[机械工程—光学工程]