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Title: Terahertz dielectric response of photoexcited carriers in Si revealed via single-shot optical-pump and terahertz-probe spectroscopy

We have demonstrated accurate observations of terahertz (THz) dielectric response due to photoexcited carriers in a Si plate via single-shot optical-pump and THz-probe spectroscopy. In contrast to conventional THz time-domain spectroscopy, this spectroscopic technique allows single-shot detection of the THz response of materials at a given delay time between the pump and THz pulses, thereby sufficiently extending the time interval between the pump pulses. As a result, we can accurately measure the dielectric properties of materials, while avoiding artifacts in the response caused by the accumulation of long-lived photoexcited carriers. Using our single-shot scheme, the transmittance of a Si plate was measured in the range of 0.5–2.5 THz with different pump fluences. Based on a Drude model analysis, the optically induced complex dielectric constant, plasma frequency, and damping rate in the THz region were quantitatively evaluated.
Authors:
; ; ; ;  [1]
  1. Department of Physics, Graduate School of Engineering, Yokohama National University, Yokohama 240-8501 (Japan)
Publication Date:
OSTI Identifier:
22485956
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 107; Journal Issue: 17; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; CARRIERS; DAMPING; DETECTION; DIELECTRIC MATERIALS; LANGMUIR FREQUENCY; PERMITTIVITY; PLATES; PULSES; PUMPS; SPECTROSCOPY