Abstract
To fabricate optical components with surface layers compatible with
high-power laser applications that may operate as antireflective
coatings, polarization rotators, or harness physical anisotropy for
other uses, metasurfaces are becoming an appealing candidate. In this
study, large-beam (1.05 cm diameter) 351-nm laser-induced
damage testing was performed on an all-glass metasurface structure
composed of cone-like features with a subwavelength spacing of
adjacent features. These structures were fabricated on untreated fused
silica glass and damage tested, as were structures that were
fabricated on fused silica glass that experienced a preliminary
etching process to remove the surface Beilby layer that is
characteristic of polished fused silica. The laser-induced damage
onset for structures on untreated fused silica glass was 19.3J⋅cm−2, while the sample that saw an initial
pretreatment etch exhibited an improved damage onset of 20.4J⋅cm−2, only 6% short of the reference
pretreated glass damage onset of 21.7J⋅cm−2. For perspective, the National
Ignition Facility operational average fluence at this wavelength and
pulse length is about 10J/cm2. At a fluence of 25.5J⋅cm−2, the reference (pretreated) fused
silica initiated 5.2 damage sites per mm2, while the antireflective metasurface
sample with a preliminary etching process treatment initiated 9.8
damage sites per mm2. These findings demonstrate that
substrate-engraved metasurfaces are compatible with high energy and
power laser applications, further broadening their application
space.
Funder
U.S. Department of Energy
Lawrence Livermore National
Laboratory
Laboratory Directed Research and
Development
Subject
Atomic and Molecular Physics, and Optics,Engineering (miscellaneous),Electrical and Electronic Engineering