There is a general need for thin optics for high power laser systems as it is best to minimize light propagation through the bulk medium to reduce the risk of laser damage. Metaoptics, or components in which the optical properties are controlled by subwavelength features decorating the surface of the optic rather than the material composition of the optic itself, can be used for thin lens fabrication, aberration correction, specialized gratings, and more generally flat 'freeform' optics.
This LLNL invention concerns a method for patterning the index of refraction by fabricating a spatially invariant metasurface, and then apply spatially varied mechanical loading to compress the metasurface features vertically and spread them radially. In doing so, the index of refraction can be re-written on the metasurface, thus enabling index patterning. This process allows rapid 'rewriting' of the index on large aperture optics to generate metaoptics that benefit from the monolithic substrate-engraved features for high laser durability.
Related Publication: Eyal Feigenbaum "Laser-controlled patterning for scalable and durable all-glass metasurface for lensing, antireflection, and birefringence", Proc. SPIE PC12939, High-Power Laser Ablation VIII, PC1293910 (11 April 2024) (https://doi.org/10.1117/12.3013927)
Related LLNL technologies available for licensing:
- Birefringent Waveplate and Method for Forming a Waveplate Having a Birefringent Metasurface
- Method of producing optical element with thicker substrate engraved metasurface layer
- Low-temperature fabrication method of bulk metamaterial structures for heat sensitive materials technology
- Scalable Method of Forming Birefringent Optical Metasurfaces Operating at Very Short Wavelengths
- A Novel Method for Forming Waveplates from Common, Durable, Isotropic Optical Materials
- Allows meta-surface engraving of a wider variety of optical substrates, not just fused silica.
- Allows for the arbitrary tailoring of the refractive index profile of a substrate surface layer down to the micron level.
- Featuring the high damage threshold of the intrinsic substrate material.
- Resulting refractive index pattern can be wavelength and angle insensitive (unlike thin film multi-layer dielectric solutions).
- Resulting surface texture is ultra-hydrophobic and is in principle self-cleaning.
- Produces arbitrarily large, but thin, lightweight optical elements.
- High power laser systems for industrial and/or scientific applications
- Exotic multilayer optics and patternable refractive index optical materials for compact but highly functional AR/VR lens elements and other ancillary optical and display technologies
Current stage of technology development: TRL 2 - 3
LLNL has filed for patent protection on this invention.
U.S. Patent Application No. 2023/0204820 System and Method for Using Mechanical Loading to Create Spatially Patterned Meta Surfaces for Optical Components published 6/29/2023