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Title: Highly focused and efficient terahertz radiation generation by photo-mixing of lasers in plasma in the presence of magnetic field

Journal Article · · Physics of Plasmas
DOI:https://doi.org/10.1063/1.4890852· OSTI ID:22299844
 [1];  [2]
  1. Singh Simutech Pvt. Ltd., Bharatpur, Rajasthan 321201 (India)
  2. Jaypee Institute of Information Technology, Noida 201307 (India)

A mechanism of efficient and highly focused terahertz (THz) radiation generation by photo-mixing of top-hat like lasers with frequencies ω{sub 1}, ω{sub 2} and wave numbers k{sub 1}, k{sub 2} in pre-formed rippled density (corrugated) plasma is proposed. In this mechanism, intensity variation of lasers offers nonlinear ponderomotive force at frequency ω{sup ′}=ω{sub 1}−ω{sub 2} and wave number k{sup ′}=k{sub 1}−k{sub 2} which couples with density ripples in the plasma and leads to a strong nonlinear oscillatory current that resonantly excites highly focused and intense THz radiation at frequency ω{sub UH}=√((ω{sub p}{sup 2}+ω{sub c}{sup 2})) (where ω{sub c} is electron cyclotron frequency). The efficiency of emitted THz radiation of the order of 15% is obtained under optimum conditions. It is observed that focus and intensity of emitted radiation can be controlled by selecting a proper profile index of the lasers, ripple parameters, and tuning of external magnetic field.

OSTI ID:
22299844
Journal Information:
Physics of Plasmas, Vol. 21, Issue 7; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 1070-664X
Country of Publication:
United States
Language:
English