Terahertz radiation emission as a result of femtosecond laser beam interaction with liquid metal droplets

Terahertz radiation emission from the photoexcited metallic microdroplets was observed for the first time. We found two separated in time femtosecond pulses excitation scheme to be efficient for such targets, while signal at one-pulse excitation was negligible. Spectral and polarization properties of the emitted terahertz radiation and its dependence on delay between pulses were measured.