Dastrup Blake S, Miedaner Peter R, Zhang Zhuquan, Nelson Keith A
Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 01239, USA.
Rev Sci Instrum. 2024 Mar 1;95(3). doi: 10.1063/5.0179123.
We demonstrate optical pump-THz probe (OPTP) spectroscopy with a variable external magnetic field (0-9 T), in which the time-dependent THz signal is measured by echelon-based single-shot detection at a repetition rate of 1 kHz. The method reduces data acquisition times by more than an order of magnitude compared to conventional electro-optic sampling using a scanning delay stage. The approach illustrates the wide applicability of the single-shot measurement approach to non-equilibrium systems that are studied through OPTP spectroscopy, especially in cases where parameters such as magnetic field strength (B) or other experimental parameters are varied. We demonstrate the capabilities of our measurement by performing cyclotron resonance experiments in bulk silicon, where we observe B-field-dependent carrier relaxation and distinct relaxation rates for different carrier types. We use a pair of economical linear array detectors to measure 500 time points on each shot, offering an equivalent performance to camera-based detection with possibilities for higher repetition rates.
我们展示了在可变外部磁场（0 - 9 T）下的光泵浦 - 太赫兹探测（OPTP）光谱，其中随时间变化的太赫兹信号通过基于阶梯的单次探测以1 kHz的重复率进行测量。与使用扫描延迟阶段的传统电光采样相比，该方法将数据采集时间减少了一个多数量级。这种方法说明了单次测量方法在通过OPTP光谱研究的非平衡系统中的广泛适用性，特别是在磁场强度（B）等参数或其他实验参数变化的情况下。我们通过在体硅中进行回旋共振实验来展示我们测量的能力，在该实验中我们观察到与磁场相关的载流子弛豫以及不同载流子类型的明显弛豫率。我们使用一对经济的线性阵列探测器在每次测量中测量500个时间点，提供与基于相机的探测相当的性能，并且有可能实现更高的重复率。
