Open AccessTerahertz white-light pulses from an air plasma photo-induced by incommensurate two-color optical fields
Author(s) -
Mark D. Thomson,
Volker Blank,
Hartmut G. Roskos
Publication year - 2010
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.18.023173
Subject(s) - optics , terahertz radiation , bandwidth (computing) , plasma , polarization (electrochemistry) , high harmonic generation , materials science , electric field , excitation , second harmonic generation , brewster's angle , white light , nonlinear optics , optoelectronics , laser , physics , telecommunications , chemistry , brewster , quantum mechanics , computer science
We demonstrate plasma-THz generation in ambient air with two-color (ω-2ω) optical excitation using input pulses with a bandwidth supporting sub-20-fs duration, yielding a continuous bandwidth exceeding 100 THz with no significant roll-off and a pulse energy of 360 nJ at a 1-kHz repetition rate. The key aspect in achieving this performance is an optimized geometry of the second-harmonic generation (SHG) crystal, producing a 2ω-field detuned from the second-harmonic of the ω-field, which promotes both a high polarization bandwidth and optimal ω-2ω temporal overlap in the plasma, as supported by theoretical results.