Infrared photonic to plasmonic couplers using spray deposited conductive metal oxides
| Autor: | Farnood Khalilzadeh-Rezaie, Justin W. Cleary, Evan M. Smith, Shivashankar Vangala, Robert E. Peale, Isaiah O. Oladeji, Kevin D. Leedy, Ricky Gibson |
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| Rok vydání: | 2017 |
| Předmět: |
Materials science
Silicon Infrared business.industry Surface plasmon Physics::Optics chemistry.chemical_element 02 engineering and technology Grating 021001 nanoscience & nanotechnology 01 natural sciences Surface plasmon polariton 010309 optics Optical coating Optics chemistry 0103 physical sciences Optoelectronics 0210 nano-technology business Plasmon Transparent conducting film |
| Zdroj: | SPIE Proceedings. |
| ISSN: | 0277-786X |
| DOI: | 10.1117/12.2254315 |
| Popis: | In recent years, infrared plasmonics has turned towards materials that are wavelength and application tailorable, and which are geared towards CMOS processing. The transparent conductive oxides are very favorable towards infrared plasmonic applications for a number of reasons, one of which being the natural visible transparency due to their relatively large bandgap. Fluorine-doped tin oxide (FTO) is one such transparent and doping-tunable material that in addition is low cost due to spray deposition techniques that result in perfectly conformal coatings. In this work, a deposition recipe that gives high free carrier concentration was used to fabricate structures for demonstration of surface plasmon excitation. 1D gratings with a range of structural parameters were etched in silicon. Then the gratings were conformally coated with FTO by aqueous spray deposition. Excitation of surface plasmon polaritons (SPP) at mid- and long- wave infrared wavelengths on these gratings was demonstrated. The observed (SPP) excitation resonances agree will with analytical excitation calculations and numerical simulations. We show that grating heights of ~10-15% of the wavelength are optimum for achieving the strongest sharpest coupling to plasmonic resonances in the mid- and longwave infrared. The presented results are compared with similar etched silicon gratings coated with Ga-doped ZnO (GZO). The dominant difference between our FTO and GZO measurements is the free carrier concentration. The useful wavelength range is predicted for FTO based plasmonics and compared with other plasmonic host materials. The work presented here could play a key role in novel decreased-cost detectors, filters, and on-chip optoelectronics. |
| Databáze: | OpenAIRE |
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