Grayscale stencil lithography for patterning multispectral color filters
- 4 September 2020
- journal article
- research article
- Published by Optica Publishing Group in Optica
- Vol. 7 (9), 1154-1161
- https://doi.org/10.1364/optica.389425
Abstract
Flat optics for spatially resolved amplitude and phase modulation usually rely on 2D patterning of layered structures with spatial thickness variation. For example, Fabry-Perot-type multilayer structures have been applied widely as spectral filter arrays. However, it is challenging to efficiently fabricate large-scale multilayer structures with spatially variable thicknesses. Conventional photo/eBeam-lithography-based approaches suffer from either low-efficiency and high-cost iterative processes or limitations on materials for spectral tunability. In this work, an efficient and cost-effective grayscale stencil lithography method is demonstrated to achieve material deposition with spatial thickness variation. The design of stencil shadow masks and deposition strategy offers arbitrarily 2D thickness patterning with low surface roughness. The method is applied to fabricate multispectral reflective filter arrays based on lossy Fabry-Perot-type optical stacks with dielectric layers of variable thickness, which generate a wide color spectrum with high customizability. Grayscale stencil lithography offers a feasible and efficient solution to overcome the thickness-step and material limitations in fabricating spatially thickness-varying structures. The principles of this method can find applications in micro-fabrication for optical sensing, imaging, and computing. (C) 2020 Optical Society of America under the terms of the OSA Open Access Publishing AgreementKeywords
Funding Information
- Air Force Office of Scientific Research (FA9550-12-1-0488)
- King Abdullah University of Science and Technology (OSR-2016-CRG5-2950-01)
- Exxon Mobil Corporation
- Agency for Science, Technology and Research
This publication has 33 references indexed in Scilit:
- Imaging with flat optics: metalenses or diffractive lenses?Optica, 2019
- Metalenses: Versatile multifunctional photonic componentsScience, 2017
- Tunable metasurfaces via subwavelength phase shifters with uniform amplitudeScientific Reports, 2017
- Wide bandwidth and high resolution planar filter array based on DBR-metasurface-DBR structuresOptics Express, 2016
- Large-Area, Lithography-Free Super Absorbers and Color Filters at Visible Frequencies Using Ultrathin Metallic FilmsACS Photonics, 2015
- Multispectral Filter Arrays: Recent Advances and Practical ImplementationSensors, 2014
- Flat optics with designer metasurfacesNature Materials, 2014
- Nanometre optical coatings based on strong interference effects in highly absorbing mediaNature Materials, 2012
- Ultrabroadband Light Absorption by a Sawtooth Anisotropic Metamaterial SlabNano Letters, 2012
- 99% efficiency measured in the -1st order of a resonant gratingOptics Express, 2005