Abstract

Vulcan, based at the STFC Central Laser Facility, is a 1PW glass laser delivering pulses with focused intensities up to 10²¹Wcm⁻², energies up to 650J and durations down to 500 fs. We are developing an upgrade to deliver 20PW peak intensity pulses to enable, for example, ultrarelativistic phenomena and studies of high intensity quantum electrodynamics. Increasing the energy is not practical in a single beam geometry due to already reaching the laser induced damage threshold on meter scale gratings, leading to the adoption of shorter and thus larger bandwidth pulses. The Vulcan 20PW upgrade is based on the generation of 820–1000nm (sub20fs compressed) pulses from a novel chirpedpulse compensated optical parametric chirped pulse amplifier (CPOPCPA) [1]: broadband collinear phase matching is achieved by appropriately chirping the pump and seed such that at any moment in time, the instantaneous frequencies of the pump and signal are perfectly phase matched (Fig. 1a). Since the scheme is collinear, the idler (which is used to seed the power amplifiers) does not exhibit any angular dispersion, compared to noncollinear schemes more typically employed. Tunability of the idler spectrum can be achieved by selection of the pump/signal frequencies and crystal phase matching angle.

© 2015 IEEE