Open AccessPolycrystalline metasurface perfect absorbers fabricated using microsphere photolithography
Author(s) -
Chuang Qu,
Edward C. Kinzel
Publication year - 2016
Publication title -
optics letters/optics index
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.524
H-Index - 272
eISSN - 1071-2763
pISSN - 0146-9592
DOI - 10.1364/ol.41.003399
Subject(s) - photoresist , photolithography , materials science , nanolithography , optics , lithography , optoelectronics , microsphere , photonics , diffraction , resist , insulator (electricity) , fabrication , nanotechnology , physics , medicine , alternative medicine , layer (electronics) , pathology , chemical engineering , engineering
Microsphere photolithography (MPL) is a practical, cost-effective nanofabrication technique. It uses self-assembled microspheres in contact with the photoresist as microlenses. The microspheres focus incident light to a sub-diffraction limited array of photonic jets in the photoresist. This Letter explores the MPL technique to pattern metal-insulator-metal metasurfaces with near-perfect absorption at mid-wave infrared (MWIR) frequencies. Experimental results are compared to electromagnetic simulations of both the exposure process and the metasurface response. The microsphere self-assembly technique results in a polycrystalline metasurface; however, the metal-insulator-metal structure is shown to be defect tolerant. While the MPL approach imposes geometric constraints on the metasurface design, once understood, the technique can be used to create functional devices. In particular, the ability to tune the resonant wavelength with the exposure dose raises the potential of hierarchical structures.