We experimentally demonstrated terahertz (THz) wave emission from thin metal (gold) films excited by asymmetrical optical fields synthesized using an in-line phase compensator. By driving the electrons in thin metal films asymmetrically, THz wave emission is observed at normal incidence of two-color pump beams. Coherent control of THz wave emission from metal films suggests that a mechanism sim...

The use of beam interference in combination with a large-area photoconductive emitter for the generation of pulsed terahertz (THz) radiation is presented. An interference pattern with a period twice that of the THz emitter is generated with a transmission phase grating, placed directly in front of the photoconductive emitter. This way, efficient THz generation is achieved with a single metallis...

Terahertz electromagnetic fields are non-ionizing electromagnetic fields in the frequency range from 0.1 to 10 THz. Potential applications of these electromagnetic fields include the whole body scanners, which currently apply millimeter waves just below the terahertz range, but future scanners will use higher frequencies in the terahertz range. These and other applications will bring along huma...

During the last few years, terahertz (THz) imaging has been used to investigate artwork and historic artifacts. The application of THz imaging to mummy investigations is very attractive since it provides spectroscopic information over a broad frequency range and its radiation has proven to be harmless to human cells. However, compared with the current standard imaging methods in mummy imaging-X...

Terahertz spectra of four alanine-rich peptides with known secondary structures were studied by terahertz time domain spectroscopy (THz-TDS) and by Fourier transform infrared spectroscopy (FTIR) using a synchrotron light source and a liquid-helium cooled bolometer. At ambient temperatures the usable bandwidth was restricted to 0.2-1.5 THz by the absorbance of water. The existence of a solvation...

Terahertz (THz) waves have exhibited promising applications in imaging, sensing, and communications, especially for the next-generation wireless communications due to large bandwidth abundant spectral resources. Modulators waveguides manipulate THz are becoming key components develop relevant technologies where metamaterials extraordinary performance control free-space on-chip propagation, resp...

Abstract This paper presents the ability of Terahertz (THz) radiation in non-destructive testing composite materials used for military applications ballistic protections. The terahertz scanner was to detect defects selected elements consisting aramid fiber-reinforced composites. Two sources radiation, operated at frequencies 100 GHz and 300 GHz, were chosen. results next compared with one obtai...

Science and technologies based on terahertz frequency electromagnetic radiation (100 GHz–30 THz) have developed rapidly over the last 30 years. For most of the 20th Century, terahertz radiation, then referred to as sub-millimeter wave or far-infrared radiation, was mainly utilized by astronomers and some spectroscopists. Following the development of laser based terahertz time-domain spectroscop...

This paper presents reconfigurable frequency and polarization FSS-based with photoconductive switches in a single dual-band operation for antenna applications at the terahertz band. The band FSS unit-cell element exhibits reconfigurability between 0.62 0.7 THz. It also converts LP waves into CP over ranging from 0.59 to 0.8 THz (30% 3-dB BW). (0.42 1.03 THz) when are turned ON (0.51 0.865 OFF. ...

We report the impulsive generation of terahertz (THz) radiation with a field amplitude of more than 1.5 kV/cm at megahertz repetition rates, using an interdigitated photoconducting device. The approach provides an average THz power of 190 microW, corresponding to an optical-to-THz conversion efficiency of 2.5 x 10(-4). Optimum conditions are achieved when the excitation spot size is of the orde...