Terahertz wave amplification in gases with the excitation of femtosecond laser pulses

Journal Article · Mon Nov 19 00:00:00 EST 2007 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.2814063· OSTI ID:21016157

Jianming, Dai; Xu, Xie; Zhang, X -C ^[1]

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1. Center for Terahertz Research, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States)

We report the observation of terahertz wave amplification in gases excited by femtosecond laser pulses. When a seed terahertz wave is sent into the {approx}5 mm long plasma created by focusing a 800 nm beam and its second harmonic into nitrogen gas, a peak amplification factor of about 65% is measured with total optical excitation intensity of 8x10{sup 14} W/cm{sup 2}. The amplification effect occurs within a time scale of less than 400 fs of the onset of ionization processes due to the optical excitation pulse duration. Four-wave-mixing parametric processes during the plasma formation are proposed to be responsible for the amplification effect.

• OSTI ID: 21016157
• Journal Information: Applied Physics Letters, Vol. 91, Issue 21; Other Information: DOI: 10.1063/1.2814063; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
AMPLIFICATION
EXCITATION
GAS LASERS
GASES
HARMONIC GENERATION
IONIZATION
NITROGEN
PLASMA
PLASMA PRODUCTION
PULSES