Open AccessTheoretical research on terahertz air-breakdown coherent detection with the transient photocurrent model
Author(s) -
Hu Wang,
Kejia Wang,
Jinsong Liu,
Houmei Dai,
Zhengang Yang
Publication year - 2012
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.20.019264
Subject(s) - terahertz radiation , femtosecond , optics , photocurrent , transient (computer programming) , terahertz spectroscopy and technology , laser , physics , photomixing , plasma , high harmonic generation , materials science , four wave mixing , waveform , nonlinear optics , optoelectronics , far infrared laser , terahertz metamaterials , quantum mechanics , computer science , operating system , voltage
The physical mechanism for sensing broadband terahertz (THz) wave via using femtosecond (fs) laser induced gas plasma without any local accessory near the plasma, i.e. THz air breakdown coherent detection, is systemically investigated by utilizing the transient photocurrent model. Previous observed results, such as conversion from incoherent to coherent detection, can be numerically obtained. Further calculations and analysis show that it is through modification of the gas ionization process, and not acceleration of freed electrons or through a four-wave-mixing (FWM) process, that the THz waveforms can be encoded into the detected second harmonic (SH) signals.