現在地
Home > 関西光科学研究所 > 関西光科学研究所 | 【現地及びweb開催】第93回KPSIセミナー Ultrafast field-driven transport excited by high-repetition, quasi-single cycle light pulses with electrooptic timing modulation

関西光科学研究所

関西光科学研究所 | 【現地及びweb開催】第93回KPSIセミナー Ultrafast field-driven transport excited by high-repetition, quasi-single cycle light pulses with electrooptic timing modulation

掲載日:2022年10月29日更新
印刷用ページを表示

関西光科学研究所 >> KPSIセミナー >> Ultrafast field-driven transport excited by high-repetition, quasi-single cycle light pulses with electrooptic timing modulation

セミナー

第93回KPSIセミナー(現地及びweb開催)

Ultrafast field-driven transport excited by high-repetition, quasi-single cycle light pulses with electrooptic timing modulation
電気光学時間変調器を用いた高繰返し準単一周期光パルスにより励起された超高速場駆動電子輸送

講演者 栗原 貴之 助教(東京大学物性研究所)
Dr. Takayuki Kurihara (Institute for Solid State Physics, The University of Tokyo)
日時 2022年11月9日(水曜日)13時30分~14時30分
会場 B251室(およびオンライン)
使用言語 日本語
要旨 [PDFファイル/386KB]

Ultrafast field-driven transport excited by high-repetition, quasi-single cycle light pulses with electrooptic timing modulation
電気光学時間変調器を用いた高繰返し準単一周期光パルスにより励起された超高速場駆動電子輸送

栗原 貴之 助教(東京大学物性研究所)
Dr. Takayuki Kurihara (Institute for Solid State Physics, The University of Tokyo)

概要 (Abstract)

     Field-induced electronic transport in solids driven by phase locked laser pulses allows the investigation of spatiotemporal properties in condensed matter system at ultrafast timescales in the femto- to even attosecond ranges. It thus started to attract great attention in recent years, especially from the context of realizing nanoscale imaging of the electronic wavepackets by combining scanning microscopy with ultrafast light pulses [1]. In such experiments, MHz repetition rate is preferred to avoid special charge and saturation effects, in contrast to the traditional high-field experiments such as high-harmonics generation wherein kHz laser repetition rates are typically used. Under such high repetition rates, how to modulate the pump pulse becomes critically important. The intensity modulation, as conventionally used for the optical pump-probe experiments, lacks sensitivity because e.g. thermal offset signals lasting beyond the intrapulse distance contaminate the relevant ultrafast dynamics occurring at much shorter time scales.
To overcome this problem, we introduced a technique called timing modulation scheme [2] and incorporated it into a 40 MHz EDF-based, phase-stable single-cycle light source [3]. In this scheme, the arrival timing of the pump pulse is electrooptically switched either before or after the probe pulse and the difference signal between them is extracted. In parallel, the system delivers passively carrier-envelope-phase locked pulses, with octave-spanning spectrum and pulse duration compressed down to 4.2 fs. As a benchmark demonstration of the system, we show that the developed system is capable of inducing field-induced transport in InGaAs by means of quantum interference current (QIUC), and to record its transient changes induced by the timing-modulated optical pumping. As a result, the decay dynamics of the photoexcited carriers has been successfully resolved, opening route to the possible attosecond transport experiment using near-infrared pulses in future.

References
[1]    T. L. Cocker, et al., Nature 539, 263–267 (2016). 
[2]    C. Traum et al., Rev. Sci. Instrum. 90, 123003 (2019)
[3]    C. Schoenfeld, T.K. et al., Opt. Lett., OL 47, 3552–3555 (2022)

[前の記事]
【現地及びweb開催】第92回KPSIセミナー Exploring Novel Photofunctions of Organic-Inorganic Nanohybrids​

Adobe Reader

PDF形式のファイルをご覧いただく場合には、Adobe社が提供するAdobe Readerが必要です。
Adobe Readerをお持ちでない方は、バナーのリンク先からダウンロードしてください。(無料)
Adobe Reader provided by Adobe is required to view PDF format files.