THz-Spectroscopy

THz time-domain spectroscopy is applied to detect the complex dielectric properties of solid state materials and fluids at THz frequencies (10^12 Hz). The analysis yields information on the properties of charge carriers (density and mobility) and on the structure and conductivity in fluids. 

Since THz EM-waveforms are generated by ultrafast laser pulses, electron lifetimes and recombination dynamics in dielectrics (quartz, sapphire) can be followed with picosecond temporal resolution (10^(-12) s) using pump-probe techniques.  The THz experiments are complemented by traditional optical techniques such as transient absorption.  Additionally, THz spectroscopy is applied to investigate the dynamics of adsorbed molecules on metal surfaces. 

In this experimental field you will learn the use of high-power diode lasers and ultrafast lasers, general optics and non-linear optics (second and third harmonic generation, THz generation), concepts of electronic excitation and relaxation mechanism in solids and fluids, and data acquisition with computer interfaces and programming in LABVIEW.