Femtosecond time-resolved optical pump-probe spectroscopy at kilohertz-scan-rates over nanosecond-time-delays without mechanical delay line - art. no. 041117
Femtosecond time-resolved optical pump-probe spectroscopy at kilohertz-scan-rates over nanosecond-time-delays without mechanical delay line - art. no. 041117
复制标题
DOI：
10.1063/1.2167812
复制
发表时间：
2006-01-23
影响因子：
4
通讯作者：
Köhler, K
中科院分区：
文献类型：
--
作者：
Bartels, A;Hudert, F;Köhler, K
我们展示了一种飞秒时间分辨光泵浦-探测光谱技术，它允许在没有机械延迟线的情况下以千赫兹的扫描速率扫描纳秒时间延迟。两个具有大约1GHz重复率的锁模飞秒激光器以Δ f（R）=11 kHz的固定差频链接。一个激光器提供泵浦脉冲，另一个提供探测脉冲。相对时间延迟在零和反向激光重复频率之间以速率Δ f（R）线性地倾斜，从而实现在1 ns时间延迟上的高速扫描。这种方法的优点，全光泵浦探测实验中的相干声学声子在半导体超晶格通过瞬态反射率的变化观察变得明显。在总测量时间为250 s的情况下，获得了7 x10（-8）的检测散粒噪声限制的信号分辨率。时间分辨率为230 fs。(c)2006年，美国物理学会。
We demonstrate a technique for femtosecond time-resolved optical pump-probe spectroscopy that allows to scan over a nanosecond time delay at a kilohertz scan rate without mechanical delay line. Two mode-locked femtosecond lasers with approximately 1 GHz repetition rate are linked at a fixed difference frequency of Delta f(R)=11 kHz. One laser delivers the pump pulses, the other provides the probe pulses. The relative time delay is linearly ramped between zero and the inverse laser repetition frequency at a rate Delta f(R), enabling high-speed scanning over a 1 ns time delay. The advantages of this method for all-optical pump-probe experiments become evident in an observation of coherent acoustic phonons in a semiconductor superlattice via transient reflectivity changes. A detection shot-noise limited signal resolution of 7x10(-8) is obtained with a total measurement time of 250 s. The time resolution is 230 fs. (c) 2006 American Institute of Physics.