2013/11/30 by J. A. Crosse, Ren‐Bao Liu, Ren-Bao Liu
Engineering · Physics and Astronomy · #Advanced Fiber Laser Technologies #Laser-Matter Interactions and Applications #Terahertz technology and applications #cond-mat.mes-hall
paper · pdf · doi:10.1103/physrevb.89.121202
published as Phys. Rev. B 89, 121202 (2014) · Updated to journal version with revised figure 1. 5 pages, 3 figures
openalex publication_date 2014/03/24 · arxiv created 2014/03/25 · arxiv updated 2015/01/08 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Optically excited electron-hole pairs, driven by a strong terahertz (THz) field, create high sidebands in the optical spectrum. The sideband spectrum exhibits a ``plateau'' up to a cutoff of 3.17Up, where Up is the ponderomotive energy. This cutoff is determined, semiclassically, from the maximum kinetic energy an electron-hole pair can gain from the THz field along a closed trajectory. A full quantum treatment reveals a second, classically forbidden, plateau with a cutoff of 8Up, the maximum kinetic energy an electron-hole pair can gain from the THz field along an open trajectory. The second plateau appears because a spatially separated electron and hole can still recombine if the classical excursion is less than the width of the electron-hole wave function, which occurs when the coherence time is longer than the excursion time (half the THz field period). This effect broadens the range of materials and excitation conditions where high-sideband generations can occur, thereby providing a wealth of systems for ultrafast electro-optical applications.