High power laser beams are difficult to manipulate because high light intensities damage solid materials like glass. The current method for reaching higher power levels is to use very large glass optics (e.g. NIF), spreading the power over a larger area to avoid damage. This is prohibitively costly for very high powers. To avoid impractical cost, a better solution would be to use a material that is not so easily damaged by light (e.g. plasma). Prior to this invention there were no viable methods for using plasma as a lens to focus or collimate light.
Holography fully encodes a 3D light field by imprinting its interference pattern with a reference laser beam in a nonlinear medium. By crossing two pump laser pulses in a gas jet, a hologram can be recorded as a distribution of plasma, allowing manipulation of a subsequent high-intensity probe beam. The interference between two collinear beams with distinct foci produces a plasma zone plate, a diffractive plasma lens capable of focusing or collimating light.
Image Caption: Colorized illustration from a simulation of a holographic plasma lens. The red concentric circles denote alternating high- and low-density plasma rings. The blue dot at the center represents the focused light. Image by Matthew Edwards/LLNL
Current stage of technology development: TRL 2-3
LLNL has filed for patent protection on this invention.
U.S. Patent Application No. 2022/0291429 Holographic Plasma Lenses published 09/15/2022
- Enables focusing and collimation of high power or high energy laser beams which would otherwise damage glass optics.
- Enables scaling of laser power densities to PW/cm2 levels and beyond, a million times the current GW/cm2 typical fused silica optical component damage limits.
- Holographic plasma optics can impart almost arbitrary spatial operations, and the mechanism is not limited to the creation of simple lenses.
- High Energy Density Science research facilities.
- Laser Inertial Confinement Fusion power plant development.
