Response-time improved hydrothermal-method-grown ZnO scintillator for soft x-ray free-electron laser timing-observation.

For pump and probe experiments in x-ray free-electron laser (XFEL) facilities, accurate timing synchronization between short-wavelength femtosecond pulses from XFELs and short optical pulses from other light sources is required. For this purpose, the response time of a hydrothermal-method-grown ZnO is improved by over one order of magnitude via intentional iron ion doping. The fluorescence rise- and decay-time constants are measured to be less than 10 and 100 ps, respectively. Owing to its intense fluorescence even for single pulse XFEL excitation, the timing jitter of the soft x-ray pulse and timing electronics are evaluated to be less than 70 ps.

High-energy, all-solid-state, ultraviolet laser power-amplifier module design and its output-energy scaling principle.

We demonstrate that a coaxially pumped, large-aperture ultraviolet power-amplifier module with solid-state tunable laser medium Ce(3+):LiCaAlF6 has 98-mJ, 290-nm, and 3-ns output pulses with a sufficient extraction efficiency of 25%. The detailed information of design parameters, including the gain-coefficient dependence on pump condition, is successfully accumulated for further energy scaling for a terawatt-class ultraviolet chirped pulse amplification laser system or a high-pulse-energy laser system.