[20p-E214-1~14] 4.3 Ultrafast Optics and Laser Processing

▲ [20p-E214-13] Improvement and Quantitative Evaluation of Asynchronous Optical Sampling Method using Dual-comb towards Semiconductor Physics

〇(M2)Tomohito Saito¹, Akifumi Asahara^2,3, Kouichi Akahane⁴, Kaoru Minoshima^2,3, Junko Ishi-Hayase¹ (1.Keio Univ., 2.UEC, 3.ERATO MINOSHIMA IOS, 4.NICT)

Keywords:Dual comb, Asynchronous optical sampling, Pump-probe method

It is important to measure transient responses of excitons in quantum dots (QDs) from viewpoints of fundamental and applied researches. Ultrafast nonlinear spectroscopies such as pump-probe (PP) and photon echo (PE) techniques have been traditionally used to measure population and coherent dynamics of QDs. However, as traditional PP and PE techniques use mechanical stages to scan the time delay between excitation pulses, there have been problems such as a short measurable time range, long acquisition time, and low signal-to-noise (S/N) ratio.
In order to solve these problems, we develop asynchronous optical sampling (ASOPS) technique using dual-comb light sources. In this presentation, we experimentally demonstrate the dual-comb ASOPS PP measurement with wide temporal dynamic range, short acquisition time, and high S/N ratio, that is suitable to study excitonic population dynamics in QDs. The performance of the dual-comb ASOPS method is compared to that of conventional PP method using a mechanical stage. We show the usability of dual-comb ASOPS technique for studying dynamics of QDs.