Coherently-tiled-Ti:sapphire laser amplification: a way to break the 10 Petawatt limit on the current ultra-intense lasers

After reaching a world record of 10 Petawatt (PW), the peak power development of the titanium-sapphire (Ti:sapphire) PW ultra-intense lasers has hit a bottleneck and seems to be difficult to continue increasing due to the difficulty of manufacturing larger Ti:sapphire crystals and the limitation of parasitic lasing that can consume stored pump energy. Unlike coherent beam combining, coherent Ti:sapphire tiling is a viable solution for expanding Ti:sapphire crystal sizes, truncating transverse amplified spontaneous emission (TASE), suppressing parasitic lasing and, importantly, not requiring complex space-time tiling control. Here, a theoretical analysis of the above features and an experimental demonstration of high-quality laser amplification are reported. The results show that the addition of a 2 × 2 tiled-Ti:sapphire amplifier to the today’s 10 PW ultra-intense laser is a viable technique to break the 10 PW limit and directly increase the highest peak power recorded by a factor of 4, further approaching the Exawatt-class (EW).