Full-silica metamaterial wave plate for high-intensity UV lasers
- 26 October 2021
- journal article
- research article
- Published by Optica Publishing Group in Optica
- Vol. 8 (11), 1372-1379
- https://doi.org/10.1364/optica.434662
Abstract
Bringing light–matter interactions into novel standards of high-energy physics is a major scientific challenge that motivated the funding of ambitious international programs to build high-power laser facilities. The major issue to overcome is to avoid laser intensity heterogeneities over the target that weaken the light–matter interaction strength. Laser beam smoothing aims at homogenizing laser intensities by superimposing on the target laser speckle intensities produced by orthogonal left and right circularly polarized beams. Conventional wave plates based on anisotropic crystals cannot support the laser fluences of such lasers, and the challenge is now to design wave plates exhibiting a high laser induced damage threshold (LIDT). Fused silica exhibits high LIDT, but its isotropic dielectric permittivity prevents effects on polarization retardance. Metamaterials have been widely investigated to tailor the phase and polarization of light but with plasmonic or high-refractive-index materials, and applying this approach with silica is highly challenging due to the weak optical contrast between silica and air or vacuum. Here we design and fabricate a silica-based metasurface acting almost like a quarter-wave plate in the UV spectral range, fulfilling the numerous constraints inherent to high-power laser beamlines, in particular, high LIDT and large sizes. We numerically and experimentally demonstrate that fused silica etched by deep grooves with a period shorter than the wavelength at 351 nm operates the linear-to-quasi circular polarization conversion together with a high transmission efficiency and a high LIDT. The high aspect ratio of the grooves due to the short period imposed by the short wavelength and the deepness of the grooves required to overcome the weak optical contrast between silica and air is experimentally obtained through a CMOS compatible process.Keywords
Funding Information
- CEA
This publication has 52 references indexed in Scilit:
- A Broadband, Background-Free Quarter-Wave Plate Based on Plasmonic MetasurfacesNano Letters, 2012
- Miniature Plasmonic Wave PlatesPhysical Review Letters, 2008
- Development of 91 cm size gratings and mirrors for LEFX laser systemJournal of Physics: Conference Series, 2008
- Polarization smoothing on the national ignition facilityJournal de Physique IV, 2006
- High-Energy Petawatt Capability for the Omega LaserOptics and Photonics News, 2005
- Design, optical characterization, and operation of large transmission gratings for the laser integration line and laser megajoule facilitiesApplied Optics, 2005
- Backscatter Reduction Using Combined Spatial, Temporal, and Polarization Beam Smoothing in a Long-Scale-length Laser PlasmaPhysical Review Letters, 2001
- Initial performance results of the OMEGA laser systemOptics Communications, 1997
- Random phase plates for beam smoothing on the Nova laserApplied Optics, 1993
- Improved laser-beam uniformity using the angular dispersion of frequency-modulated lightJournal of Applied Physics, 1989