Terahertz emission from a femtosecond laser focus in a two-color scheme

Journal Article · Fri Jan 15 00:00:00 EST 2010 · Journal of the Optical Society of America. Part B, Optical Physics

DOI:https://doi.org/10.1364/JOSAB.27.000016· OSTI ID:22046835

Balakin, Alexey V; Borodin, Alexander V; Shkurinov, Alexander P ^[1]; Kotelnikov, Igor A ^[2]

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1. Department of Physics and International Laser Center, M. V. Lomonosov Moscow State University, Leninskie Gory GSP-1, Moscow 119992 (Russian Federation)
2. Budker Institute of Nuclear Physics, Lavrentyev Avenue 11, Novosibirsk 630090 (Russian Federation)

We critically revise the theory of terahertz emission from a plasma filament induced in a gas media by one or two focusd femtosecond laser pulses. We distinguish a radiation pressure force (RPF) from a ponderomotive force (PF), discuss conditions for one of these forces to be the dominating contribution to the terahertz emission, and also show that the angular distribution of the emitted power critically depends on which of the two forces dominates in a particular experiment. We show that the experimentally observed periodic dependence of the emitted terahertz power on the gas pressure reveals the dominating role of the RPF over the PF, whereas the angular diagram of the emission allows us to determine the predominant direction of the force. We also emphasize that the terahertz emission originated by a transient photocurrent exhibits a different dependency from the phase difference between the first and the second harmonics of the optic laser field, which generally enables the experimental detection of the prevailing mechanism of the terahertz emission from the plasma filament.

• OSTI ID: 22046835
• Journal Information: Journal of the Optical Society of America. Part B, Optical Physics, Vol. 27, Issue 1; Other Information: (c) 2009 Optical Society of America; Country of input: International Atomic Energy Agency (IAEA); ISSN 0740-3224
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ANGULAR DISTRIBUTION
COLOR
FOCUSING
HARMONICS
LASER RADIATION
LASER-PRODUCED PLASMA
LASERS
LIGHT TRANSMISSION
MIXING
PERIODICITY
PHOTON EMISSION
PLASMA FILAMENT
PONDEROMOTIVE FORCE
PULSED IRRADIATION
RADIATION PRESSURE
THZ RANGE
TRANSIENTS