Abstract-Terahertz frequency upconversion via relativistic Doppler reflection from a photoinduced plasma front in a solid-state medium

http://prb.aps.org/abstract/PRB/v87/i8/e085203

Mark D. Thomson, Slava M. Tzanova, and Hartmut G. Roskos 
Physikalisches Institut, J. W. Goethe-Universität, Max-von-Laue-Strasse 1, 60438 Frankfurt am Main, Germany

Received 15 October 2012; published 15 February 2013

We propose and simulate the relativistic Doppler reflection of terahertz (THz) radiation normally incident on a plasma front in a semiconductor medium, resulting in a significant frequency upshift for the reflected radiation. The plasma front is generated by linear interband excitation of the semiconductor by a counterpropagating femtosecond optical pulse. High-resistivity silicon is identified as an ideal medium for experiments, as it possesses a desirable optical penetration depth, upshift factor, and low THz absorption and dispersion. The depletion of the optical pump pulse results in a spatiotemporal plasma profile, which leads to results that go beyond the existing analytic theory. We employ one-dimensional finite-difference time-domain simulations to predict the reflected THz pulses vs a range of realistic experimental parameters. The results indicate that a significant frequency upshift can be expected for both conventional and ultrabroadband THz pulses, and that this technique may be suitable to provide higher-bandwidth THz radiation extending into the midinfrared.

©2013 American Physical Society

URL:

http://link.aps.org/doi/10.1103/PhysRevB.87.085203

DOI:

10.1103/PhysRevB.87.085203

PACS:

42.65.Re, 78.47.J-, 42.72.Ai, 78.20.Bh