Efficient terahertz generation in GaSe via eee-interaction type

Using the measured and modeled dispersion properties of GaSe an efficient terahertz generation via optical rectification of femtosecond laser pulses in the several millimeters thick crystals via eee-interaction process has been predicted and demonstrated experimentally. The dielectric properties in terahertz range as well as THz generation and detection were studied in pure and doped GaSe crystals. The relative nonlinear susceptibilities of the mixed GaSe_0.977Te_0.023 and GaSe_0.71S_0.29 crystals were estimated based on the experimental data and the assumed model approach.