Dual-Frequency Comb Transient Absorption: Broad Dynamic Range Measurement of Femtosecond to Nanosecond Relaxation Processes
Dual-Frequency Comb Transient Absorption: Broad Dynamic Range Measurement of Femtosecond to Nanosecond Relaxation Processes
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DOI：
10.1021/acs.jpclett.8b00886
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发表时间：
2018-04-19
影响因子：
5.7
通讯作者：
Cho, Minhaeng
中科院分区：
文献类型：
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作者：
Kim, JunWoo;Cho, Byungmoon;Cho, Minhaeng
我们实验证明了双频梳状瞬态吸收（DFC-TA）技术，它具有12 fs的时间分辨率和超快的扫描速率。在这里，快速扫描速率是通过采用异步光学采样（ASOPS），它利用两个独立的锁模激光器与稍微失谐的重复率。ASOPS方法是有利的，因为在TA测量期间光学样品的光降解损伤可以通过门控采样最小化。我们表明，振动和电子布居弛豫的近红外染料分子在溶液中发生的时间范围从飞秒到纳秒，甚至可以解决一个单一的时间扫描测量。我们的双频梳状激光器的相位相干性被证明是成功的相干平均与飞秒时间分辨率保持在许多数据采集的关键。我们预计，目前的DFC-TA方法，而不使用任何泵探测时间延迟装置，可用于开发超快TA为基础的显微镜和时间分辨相干多维光谱。
We experimentally demonstrate a dual-frequency comb-based transient absorption (DFC-TA) technique, which has a 12 fs time resolution and an ultrafast scan rate. Here, the fast scan rate is achieved by employing asynchronous optical sampling (ASOPS), which utilizes two independent mode-locked lasers with a slightly detuned repetition rates. The ASOPS approach is advantageous because photodegradation damage of optical sample during TA measurements can be minimized by a gated sampling. We show that the vibrational and electronic population relaxations of near-IR dye molecules in solution that occur in the time range from femtoseconds to nanoseconds can be resolved even with a single time scan measurement. The phase coherent nature of our dual frequency comb lasers is shown to be the key for successful coherent averaging with femtosecond time resolution preserved over many data acquisitions. We anticipate that the present DFC-TA method without using any pump probe time delay devices could be of use in developing ultrafast TA-based microscopy and time-resolved coherent multidimensional spectroscopy.