Younesi Ali Tayefeh, Ulbricht Ronald
Opt Express. 2022 Oct 10;30(21):38896-38906. doi: 10.1364/OE.467483.
Time-resolved spectroscopy and, in particular, transient absorption methods have been widely employed to study the dynamics of materials, usually achieving time resolution down to femtoseconds with measurement windows up to a few nanoseconds. Various techniques have been developed to extend the measurement duration up to milliseconds and beyond to permit probing slower dynamics. However, most of these either demand complicated and expensive equipment or do not provide broadband spectral coverage. This paper proposes a transient absorption technique in which an ultra-short pulse laser and a broadband incoherent continuous-wave light source are employed as pump and probe, respectively. Detection of the transient probe transmission is performed in a time-resolved fashion with a fast photodiode after a monochromator and the data is recorded with an oscilloscope. The time resolution is determined by the electronic bandwidth of the detection and acquisition devices and is ∼1 ns, with a measurement duration window of up to milliseconds and a spectral resolution of <2 nm covering from 0.4 to 2 µm. In addition, the setup can be employed to measure time- and spectrally-resolved photoluminescence.
时间分辨光谱学，尤其是瞬态吸收方法，已被广泛用于研究材料的动力学，通常可实现飞秒级的时间分辨率，测量窗口可达几纳秒。已经开发了各种技术来将测量持续时间延长至毫秒及以上，以探测较慢的动力学过程。然而，其中大多数技术要么需要复杂且昂贵的设备，要么无法提供宽带光谱覆盖。本文提出了一种瞬态吸收技术，其中分别使用超短脉冲激光器和宽带非相干连续波光源作为泵浦源和探测源。瞬态探测光的透射率检测通过单色仪后用快速光电二极管以时间分辨方式进行，数据用示波器记录。时间分辨率由检测和采集设备的电子带宽决定，约为1纳秒，测量持续时间窗口可达毫秒级，光谱分辨率小于2纳米，覆盖范围为0.4至2微米。此外，该装置可用于测量时间分辨和光谱分辨的光致发光。
