Record-breaking terahertz laser beam  January 20, 2020 An international team of researchers (Greece, Austria, Qatar, Russia, Lithuania) has experimentally demonstrated that two-color filamentation of femtosecond mid-infrared laser pulses at 3.9 μm allows one to generate ultrashort sub-cycle THz pulses with sub-milijoule energy and THz conversion efficiency of 2.36%, resulting in THz field amplitudes above 100 MV cm−1. Numerical simulations predict that the observed THz yield can be significantly upscaled by further optimizing the experimental setup. They showed that the generated THz pulses are powerful enough to induce nonlinear cross-phase modulation in electro-optic crystals. The work paves the way toward free space extreme nonlinear THz optics using […]

A laser for penetrating waves  August 19, 2019 An international team of researchers (France, Poland, Germany, Russia, Czech Republic) used a heavy metal alloy of mercury, cadmium and tellurium (HgCdTe) that is used for highly sensitive thermal imaging cameras. Mercury, cadmium and tellurium contents can be very precisely chosen, which makes it possible to fine-tune the band gap. The material showed properties similar to graphene, but without the issue of strong Auger scattering. When electric current is applied it gets rid of its energy in the form of terahertz radiation. By varying an additional magnetic field of only about 200 millitesla, the experts were able […]