Ideal form of optical plasma lenses

Abstract

The canonical form of an optical plasma lens is a parabolic density channel. This form suffers from spherical aberrations, among others. Spherical aberration is partially corrected by adding a quartic term to the radial density profile. Ideal forms which lead to perfect focusing or imaging are obtained. The fields at the focus of a strong lens are computed with high accuracy and efficiency using a combination of eikonal and full Maxwell descriptions of the radiation propagation. The calculations are performed using a new computer propagation code, SeaRay, which is designed to transition between various solution methods as the beam propagates through different spatial regions. The calculations produce the full Maxwell vector fields in the focal region.

Petawatt and exawatt class lasers worldwide

“…Recently, it has been observed that by utilizing a suitable picosecond-scale pre-pulse on the surface of a plasma mirror, the scale length can be optimized [319] to minimize absorption and give reflectivities of 96% for the main pulse, Figure 39. (a) Schematic illustrating the operation principle of an ellipsoidal focusing plasma mirror to increase the intensity by a factor of five.…”

“…However, more complex gas cells with density structures, capillary discharge devices [334][335][336] and multi-pulses [337] , have been used to deliver tunable GeV-scale electron beams [230] over many centimetres of interaction length. The nonlinear plasma response can also be utilized for compressing [328] and focusing [338] short ∼30 fs beams, with expectations that they could readily handle multi-petawatt powers and deliver nearideal focusing if a suitable density profile is obtained [319] . More complex phenomena such as plasma compression and diffraction [339,340] can also be used to manipulate the beam [341] .…”

“…Recently, it has been observed that by utilizing a suitable picosecond-scale pre-pulse on the surface of a plasma mirror, the scale length can be optimized [319] to minimize absorption and give reflectivities of 96% for the main pulse, approaching that of conventional multi-layers. The new generation of high-repetition-rate lasers will require plasma optics that can be fielded at repetition rates of Hz, and tapes [320] or liquids are an obvious choice.…”

Plasma eyepieces for petawatt class lasers

“…In previously proposed plasma lenses in the nonblowout regime, where ponderomotive force is negligible a=w 2 Շ0:1, a transversely preformed plasma can perfectly resize the laser beam. [22][23][24][25] For absolute blowout cases Eq. (B10), the ponderomotive effect dominates and the laser beam cannot be focused by the plasma.…”

“…In addition, w 2 is adjustable by changing d, l, and the plasma density n p . Compared to previous studies on plasma lenses for lasers, [22][23][24][25] the herein proposed concept does not require a preformed structure and is preferably suitable for petawatt class lasers.…”