Plasma-based generation schemes of terahertz (THz) are promising and flexible sources of high-field, broadband THz pulses. The traditional plasma-generation scheme involves combining an ultrafast laser pulse with its second harmonic in a tight focus to generate a plasma from which THz radiation is emitted. We demonstrate non-traditional experimental schemes for plasma-based THz generation using multiple laser pulses. THz emission of a plasma formed by a commensurate two-color pulse (containing a near IR frequency and its second harmonic) can be enhanced by the addition of an 800-nm pulse, which is the waste light from an optical parametric amplifier. We observed enhancements of the THz electric field by a factor of up to 30. Numerical calculations done using the well-known photocurrent model are in good agreement with experimental results. These studies help suggest future avenues of improvement in practical table-top plasma generation of THz.

Date Published: 12 September 2019
PDF
Proc. SPIE 11124, Terahertz Emitters, Receivers, and Applications X, 111240A (12 September 2019); doi: 10.1117/12.2529867

Published in SPIE Proceedings Vol. 11124:
Terahertz Emitters, Receivers, and Applications X
Manijeh Razeghi; Alexei N. Baranov; Miriam S. Vitiello, Editor(s)