Octave-spanning coherent perfect absorption in a thin silicon film
| Autor: | Ayman F. Abouraddy, Walker D. Larson, Lorelle N. Pye, Soroush Shabahang, Massimo L. Villinger, Lane Martin |
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| Rok vydání: | 2017 |
| Předmět: |
Materials science
Silicon business.industry Nanocrystalline silicon chemistry.chemical_element 02 engineering and technology Dielectric engineering.material 021001 nanoscience & nanotechnology 01 natural sciences Atomic and Molecular Physics and Optics 010309 optics Wavelength Polycrystalline silicon Optics chemistry 0103 physical sciences engineering Light beam Photonics Thin film 0210 nano-technology business |
| Zdroj: | Optics letters. 42(1) |
| ISSN: | 1539-4794 |
| Popis: | Although optical absorption is an intrinsic materials property, it can be manipulated through structural modification. Coherent perfect absorption increases absorption to 100% interferometrically but is typically realized only over narrow bandwidths using two laser beams with fixed phase relationship. We show that engineering a thin film’s photonic environment severs the link between the effective absorption of the film and its intrinsic absorption while eliminating, in principle, bandwidth restrictions. Employing thin aperiodic dielectric mirrors, we demonstrate coherent perfect absorption in a 2 μm thick film of polycrystalline silicon using a single incoherent beam of light at all the resonances across a spectrally flat, octave-spanning near-infrared spectrum, ≈800–1600 nm. Critically, these mirrors have wavelength-dependent reflectivity devised to counterbalance the decline in silicon’s intrinsic absorption at long wavelengths. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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