Alignment of solid targets under extreme tight focus conditions generated by an ellipsoidal plasma mirror

The design of ellipsoidal plasma mirrors (EPMs) for the PEARL laser facility is presented. The EPMs achieve a magnification of 0.32 in focal spot size, and the corresponding increase in focused intensity is expected to be about 8. Designing and implementing such focusing optics for short-pulse (<100 fs) systems paves the way for their use in future high-power facilities, where they can be used to achieve intensities beyond 1023 W/cm2. A retro-imaging-based target alignment system is also described, which is used to align solid targets at the output of the ellispoidal mirrors (with a numerical aperture of 0.75 in this case).