High-energy terahertz generation by optical rectification at 150 TW laser power

Abstract

The interest of this thesis is to produce high-energy terahertz (THz) radiation via optical rectification in large-area nonlinear emitters by using a 150-TW laser. The power of THz waves can be measured by commercial thermal detectors. In this thesis, a calibration method using a low-duty-cycle optical chopper with a single slot is discussed to obtain the responsivity of a pyroelectric detector (PED) for THz pulses. Also, the transmission of various filters is characterized by using Fourier transform infrared spectroscopy (FTIR) and terahertz time-domain spectroscopy (THz-TDS). Here, experimental results on energy-scalable THz generation by using large-diameter (>75 mm) single-wafer lithium niobate (LN) are reported. The responsivity of the PED and filter transmission spectra are carefully calibrated and characterized to accurately measure the absolute energy of THz radiation.