Measurement of tunable terahertz drive laser pulse train generation using streak camera

A pulse-train with tunable terahertz (THz) repetition rate can be used for driving a photocathode radio-frequency (RF) electron gun to generate electron microbunch train, which is indispensable for exciting intense narrowband THz radiation. In this paper, a train of 8 laser micro-pulses is experimentally obtained and measured by a 3-stage polarization-beam-splitter-based pulse stacker and a streak camera respectively. In addition, we performed measurements of the generation of tunable THz pulse-train with the interpulse spacings of 12.0, 9.8, and 6.3 ps, corresponding to modulated repetition frequencies of 0.089, 0.103, and 0.148 THz, respectively. As a result, preliminary experiments prove the feasibility and applicability of tunable THz laser pulse train generation based on the polarization-beam-splitter-based pulse stacking system and the streak camera measurement system.