“ High Power Terahertz. ”
by Dr. Indranuj Dey (DNAP, TIFR Mumbai)
at P - 305
The generation of intense sub-picosecond pulses in the terahertz (THz) spectral range (∼ 0.1–20 THz) using table-top ultra-short pulse lasers is an important and contemporary area of research in the field of ultra-fast spectroscopy. The potential uses for such radiation include, THz probing of semiconductors and molecules, study of ultrafast electron dynamics, and non-linear THz spectroscopy. The main emphasis of the research is the efficient generation of few – cycle THz pulse with peak energies of the order of 10s of mJ to a few mJ, utilizing the non-linear interaction of an intense femtosecond laser pulse with matter. We have recently initiated some experiments in this regard at the UPHILL facility, utilizing the 20 Terawatt – 40 femtosecond laser system. In our recent experiments, generation of THz pulse from filamentation in various transparent media has been studied, leading to some interesting observations. An overview of these experimental results would be presented in this talk along with some discussion of the possible physical phenomenon responsible for the intense THz generation.