Characterization of 700  μJ T rays generated during high-power laser solid interaction

Abstract

Laser-produced solid density plasmas are well-known as table-top sources of electromagnetic radiation. Recent studies have shown that energetic broadband terahertz pulses (T rays) can also be generated from laser-driven compact ion accelerators. Here we report the measurement of record-breaking T-Ray pulses with energies no less than 0.7 mJ. The terahertz spectrum has been characterized for frequencies ranging from 0.1-133 THz. The dependence of T-Ray yield on incident laser energy is linear and shows no tendencies of saturation. The noncollinear emission pattern and the high yield reveal that the T rays are generated by the transient field at the rear surface of the solid target.

An investigation on THz yield from laser-produced solid density plasmas at relativistic laser intensities

“…It has been effectively used to generate high frequency radiation [1], ultra large quasistatic electric and magnetic fields [2,3], accelerated particle beams [4,5] etc. In recent years we have witnessed a remarkable interest in utilizing this process for coherent terahertz generation [6][7][8]. This is due to the fact that the plasma produced during such an interaction has many advantages over other well established terahertz generation methods due to their compactness, high damage threshold and high conversion efficiency [7].…”

Aligned copper nanorod arrays for highly efficient generation of intense ultra-broadband THz pulses

“…Intense transition radiation in the THz frequency range has been observed when energetic electrons generated by high-intensity laser-solid interaction are ejected from the target2627. THz pulses (0.1–133 THz) with pulse energy more than 700 μJ have been demonstrated from rear side of a foil target via a different mechanism; THz generation via target normal sheath acceleration2428. Intense THz pulses via generation of coherent transition radiation in the rear side of size limited thin targets have also been demonstrated by Liao et al 27…”

Smith–Purcell radiation in the terahertz regime using charged particle beams from laser–matter interactions

“…The maximum observed proton energy for this measurement was 1.7 MeV. In previous experiments (Gopal et al, 2013b), peak energies upto 4.7 MeV were generated. We believe this variation in the peak particle energy is due to the non-optimal performance of the laser during the experimental campaign.…”

“…In return, laser-matter interaction and laser-based accelerator schemes were successfully tested to generate coherent radiation in the far ends of the electromagnetic spectrum (Murnane et al, 1991;Hamster et al, 1993;Macklin et al, 1993;Schlenvoigt et al, 2008). Latest addition to these studies is the generation of gigawatt (GW) power radiation in the terahertz band of the electromagnetic spectrum by a compact laser-driven accelerator (Gopal et al, 2013b). Laser-driven ion accelerators extend the unique possibility to generate multiple high-power tunable terahertz pulses with variable time delay, which will enable pump-probe studies in materials, otherwise not feasible (Jones et al, 1993;Back et al, 1998;Kampfrath et al, 2013).…”