Terahertz radiation from bismuth surface induced by femtosecond laser pulses

Abstract

We report on the first experimental observation of terahertz (THz) wave generation from bismuth mono- and polycrystalline samples irradiated by femtosecond laser pulses. Dependencies of the THz signal on the crystal orientation, optical pulse energy, incidence angle, and polarization are presented and discussed together with features of the sample surfaces. The optical-to-THz conversion efficiency was up to two orders of magnitude higher than for metal at a moderate fluence of ∼1 mJ/cm². We also found nonlinear effects not previously observed using other metal and semiconductor materials: (a) asymmetry of THz response with respect to a half-turn of a sample around its normal, (b) THz polarization control by orientation of the sample surface, and

Dual THz Wave and X-ray Generation from a Water Film under Femtosecond Laser Excitation

“…Various solution samples can be utilised as targets, since X-ray emission from water is also enhanced by the addition of electrolyte [ 39 ] and gold nano-particles [ 40 ]. Other materials such as bismuth [ 55 ] and copper [ 56 ] can be also used as targets at the tested high-irradiance conditions. Interaction of the X-ray or THz wave with matter originates with electrons at keV or meV, in other words with electrons bound in inner-shells or with structural absorption resonances, respectively.…”

Effect of Antimony Buffer Layer on the Electric and Magnetic Properties of 200 and 600 nm Thick Bismuth Films on Mica Substrate

“…It was shown [6,7] that the most promising materials for THz devices may be semimetals: Bi, Sb, As, etc. All of them are solid solutions.…”

“…All of them are solid solutions. The response of transport phenomena on THz emission in single-crystal Bi was discovered in the work [6]. Bismuth is anisotropic material, its properties are sensitive to crystal orientation [6].…”

“…The response of transport phenomena on THz emission in single-crystal Bi was discovered in the work [6]. Bismuth is anisotropic material, its properties are sensitive to crystal orientation [6]. The films of bismuth are sensitive to the classic size effect [8].…”