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We present a comparative thermo-optical study of various gain media geometries to minimize depolarization losses and wavefront distortions for a concept of 10 J/ 100 Hz cryo HEC-DPSSL based on 10 J/10 Hz Bivoj/DiPOLE system.

We present a new PW beamline for Vulcan facility with the focus on the ps Front End. This fully OPCPA system is designed to deliver 30 J, 30 fs pulses with a 5 min repetition rate.

We describe the application of the adhesive-free bonding (AFB) technique to form crystalline Yb:YAG gain media slabs. We demonstrate that the AFB technique is a viable alternative for producing large aperture slabs for high-energy lasers.

We propose the application of the Gas Cluster Ion Beam (GCIB) and of the Accelerated Neutral Atom Beam (ANAB) surface treatments to ceramic Yb:YAG gain material and demonstrate their suitability for high energy laser applications.

In this paper we present our plans for an auxiliary OPCPA beamline for the Vulcan PW laser facility. It will be capable of delivering 30J

We report on the development of a 100 J, 10 Hz cryogenic gas cooled multi-slab Yb:YAG DPSSL system capable of generating temporally shaped pulses from 2 ns to 15 ns. This system will be used for high energy density (HED) experiments at the European X-ray Free Electron Laser (XFEL) facility.

We report a novel method to accurately evaluate the impact of stretcher gratings on the contrast pedestal of high power laser pulses by precise quantitative characterization of the grating surface. The results are in a good agreement with the experimental measurement. We have, for the first time, established a relation between the contrast pedestal and natural property of stretcher gratings.

We explore how the DiPOLE architecture, based on diode-pumped, cryo-cooled Yb:YAG, could be adapted for direct-CPA ps-pulse generation and conclude that generation of 2 ps, 70 J pulses at 10 Hz repetition rate is feasible.

In this paper we describe the progress of energy scaling cryogenic gas-cooled Yb:YAG amplifier technology from a 10 J, 10 Hz prototype to delivering 100 J pulses at 1 Hz. The architecture of the prototype system (DiPOLE) is presented, highlighting the key design characteristics that enable energy scaling, along with the improvements that have allowed development of a 100J-level system (DiPOLE100).

This talk will describe our programmes to scale diode pumped PW and parametric systems to high average power as a new basis for applications based on compact, efficient and reliable secondary sources.

We present results for a 150 mJ, 10 Hz, ns front end system for a 100 J DPSSL. The system incorporates arbitrary temporal pulse shaping, in addition to passive and active spatial shaping of the output.

We report on the recent contrast enhancement of Astra-Gemini laser. It is shown that the stretcher gratings contribute significantly to the contrast pedestal. Implementing higher-quality gratings resulted in a significant contrast improvement. We have also investigated and quantified the contribution to the contrast pedestal from each individual grating in the stretcher.

We present preliminary results for DiPOLE, a cryogenic Yb:YAG DPSSL amplifier using a temporary extraction architecture. Measured average powers and optical-to-optical efficiencies already compare favourably to existing systems.

Usually, the raison d’etre for investment in high power laser systems has been rightly associated with the “extreme” science that is made possible via their development. Nowhere is this more true than at the Rutherford Appleton Laboratory, which for many years has been home to some of the worlds most powerful “peak power” laser systems. The Vulcan PW (Nd:glass) and dual beam Gemini PW (Ti:S) systems are good recent examples of this and a planned upgrade to the Vulcan system raising its power to up to the 20 PW level based on an OPCPA approach further underpins the rationale that lies behind this.

We report on the recent progress in the contrast campaign for Astra-Gemini laser. An extensive experimental study shows that the main contributions to the “coherent” contrast feature come from the stretcher gratings. Implementing higher-quality gratings resulted in a significant contrast enhancement. Further enhancement by 4 orders of magnitude was also demonstrated using double plasma mirrors (DPM). In addition, the replica prepulses were greatly suppressed or eliminated by employing the wedged crystals and optics, providing a very clean laser pulse.

We present recent amplification results for DiPOLE, a cryogenic gas cooled multi-slab Yb:YAG amplifier, demonstrating efficient operation with pulse energies of 10.1 J at 1 Hz and 6.4 J at 10 Hz.

We report on the recent progress in contrast campaign for Astra-Gemini laser. An experimental study shows that the main contributions to the so-called “coherent” contrast feature come from the diffraction gratings in the stretcher. Replacing the gratings by higher-quality optics resulted in contrast enhancement by an order of magnitude. Further enhancement of coherent contrast by 4 orders of magnitude was also demonstrated using double plasma mirrors (DPM). The replica prepulses were also greatly suppressed in new amplifiers by employing the wedged crystal and optics to provide very clean laser pulses.

We demonstrate experimentally that the “coherent” contrast pedestal in compressed pulses from CPA lasers originates from the diffraction gratings in the pulse stretcher. The pedestal intensity correlates with the level of scatter from the gratings.

We present modelling results for a 1 kJ diode-pumped laser system, based on cryogenic gas-cooled multi-slab Yb:YAG amplifiers.

We have developed a closed loop program using a wavefront sensor that is used to measure the tip / tilt and piston between the two beams for coherent combination with the laser in CW mode.

I will describe a UK project to establish a 10-20 PW capability on the Vulcan Laser at the Rutherford Appleton Laboratory based on the OPCPA technique. Design, new technology, science and status will be covered. Article not available.

We report an investigation of the temporal contrast of the Astra-Gemini high power laser. Enhanced contrast by nearly an order of magnitude has been achieved by upgrading the commercial front-end to provide cleaner seed pulses.

We present the development of a novel large bandwidth front-end that is capable of supporting sub 30fs pulses, with 0.4J of energy at a 2Hz repetition rate that is centered at 910nm

ELI has been put on the European Roadmap for Research infrastructures by the European Strategy Forum on Research Infrastructures (ESFRI). It will be the first Paneuropean Infrastructure utilizing an ultra-intense laser with a peak-power of 200 PW for interaction experiments with electric field strength well above the PV/m (1015 V/m ). With the high focused intensity (above 4 × 1024W/cm2) it will be possible to enter the ultra-relativistic regime when protons are accelerated to nearly the speed of light at a distance in the order of the wavelength of the driving extreme light. Fundamental physics phenomena can be investigated for the first time including nonlinear vacuum interaction and pair generation. ELI intermediate beam lines with peak-powers in the few PW range but higher repetition rates (10 Hz) will enable scientific and societal including medical applications based on laser particle acceleration (proton therapy) and x-ray generation. The photonuclear facility will explore nuclei with hard x-ray and gamma-ray photons produced by high intensity interaction with matter. The Attosecond science laser driver with its high repetition rate (1 kHz) and high average power (>1 kW, 5–10fs) opens the way to ultrafast investigations in different scientific and technological areas with time resolutions in the Attosecond and may by even faster (zeptosecond) time domains using very brilliant VUV-light and x-rays generated by harmonics from gases or solids.

I will review recent scientific highlights from the UK’s high power laser programme and discuss our plans to establish a 10 PW capability on the existing Vulcan PW facility, including its anticipated scientific programme.