Second-harmonic generation from subwavelength metal heterodimers
| Autor: | Avi Niv, Mandira Pal, Esti Toledo, Yonatan Sivan, Maya H. Shor Peled, Mark Schvartzman, Shilpi Shital, Achyut Maity |
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| Rok vydání: | 2020 |
| Předmět: |
Physics::Optics
02 engineering and technology 01 natural sciences Molecular physics 010309 optics Metal Condensed Matter::Materials Science Optics 0103 physical sciences Physics::Atomic and Molecular Clusters Coulomb Physics Quantitative Biology::Biomolecules business.industry Quantitative Biology::Molecular Networks Second-harmonic generation 021001 nanoscience & nanotechnology Atomic and Molecular Physics and Optics Nonlinear system visual_art visual_art.visual_art_medium Particle 0210 nano-technology business Order of magnitude Visible spectrum |
| Zdroj: | Optics express. 28(21) |
| ISSN: | 1094-4087 |
| Popis: | We experimentally study the optical second-harmonic generation (SHG) from deep subwavelength gold-silver heterodimers, and silver-silver and gold-gold homodimers. Our results indicate a heterodimer SHG that is an order of magnitude more intense than that of the homodimers. In contrast, full-wave calculations that consider the surface and bulk contribution of individual particles, which is the conventional view on such processes, suggest that it is the silver-silver homodimer that should prevail. Based on the deep subwavelength dimension of our structure, we propose that the heterodimer nonlinearity results from a Coulomb interaction between lumped oscillating charges and not from the surface nonlinearity of each particle, as convention would have it. Our proposed model can explain the larger SHG emission observed in gold-silver heterodimers and reproduces its unique spectral lineshape. |
| Databáze: | OpenAIRE |
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