Characterization of 700 μJ T rays generated during high-power laser solid interaction

Laser produced solid density plasmas are well known as table top sources of electromagnetic radiation. Recent studies have shown that energetic broadband THz pulses can also be generated from laser driven compact ion accelerators. Here we report the measurement of record breaking T-ray pulses with energies no less than 700 micro-joules. THz spectrum has been characterized for frequencies ranging from 0.1-133 THz. The dependence of T-ray yield on incident laser energy is linear and shows no tendencies of saturation. Non-collinear emission pattern and the high yield reveals that the T-rays are generated by the transient field in the normal direction at the rear surface of the solid target.