Researchers in optics have improved their revolutionary metasurface masking technology to make higher features without widening the space between them, a development that opens up interesting new design opportunities.
They have improved the masking technology to produce metasurfaces that permit an antireflection layer to have a wide optical bandwidth and a wide range of incidence angles. Remarkably, they can now span a bandwidth range that extends from ultraviolet to wavelengths longer than 2 microns. With the technology at the time, that was not feasible.
The masking technology aims to improve the stability and durability of the optic by replacing the requirement for broadband anti-reflective (AR) coatings with a monolithic metasurface to the optic, effectively becoming a seamless component of the optic. Additionally, the group has demonstrated and is still working on other modifications of this technique, including sub-micron thick optical components such as lenses and polarization-altering waveplates. Such metasurface optics might be revolutionary for the most sophisticated laser systems, replacing several optics with a single, stronger, thinner optic.
An all-glass metasurface is produced using their four-step procedure, which entails the deposition of an ultrathin metal sheet, dewetting, etching, and mask removal. Although a straightforward technique, it offers great control and tunability over metasurface properties. Their most recent improvements resulted from two important modifications to their process: switching from gold to platinum as the deposition material and improving the dewetting mask technology.
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