Terahertz and second-harmonic generation in reflection at the surface of a dielectric crystal using a double pulse laser excitation

We present an original THz generation/detection configuration using an autocorrelation technique. By second-order nonlinear effects, THz and SH signals are generated in reflection at the surface of a dielectric crystal and detected simultaneously. This technic, by detecting weak and broadband THz signals, could be useful for surface spectroscopy.