Photonics Research, 2018, 6 (5): 05000B82, Published Online: Jul. 6, 2018
Inverse-designed photonic fibers and metasurfaces for nonlinear frequency conversion [Invited] Download: 685次
Computational electromagnetic methods Nonlinear optics, fibers Harmonic generation and mixing Nonlinear optics, devices Nanophotonics and photonic crystals
Abstract
Typically, photonic waveguides designed for nonlinear frequency conversion rely on intuitive and established principles, including index guiding and bandgap engineering, and are based on simple shapes with high degrees of symmetry. We show that recently developed inverse-design techniques can be applied to discover new kinds of microstructured fibers and metasurfaces designed to achieve large nonlinear frequency-conversion efficiencies. As a proof of principle, we demonstrate complex, wavelength-scale chalcogenide glass fibers and gallium phosphide three-dimensional metasurfaces exhibiting some of the largest nonlinear conversion efficiencies predicted thus far, e.g., lowering the power requirement for third-harmonic generation by 10 4 and enhancing second-harmonic generation conversion efficiency by 10 7 . Such enhancements arise because, in addition to enabling a great degree of tunability in the choice of design wavelengths, these optimization tools ensure both frequency- and phase-matching in addition to large nonlinear overlap factors.
Chawin Sitawarin, Weiliang Jin, Zin Lin, Alejandro W. Rodriguez. Inverse-designed photonic fibers and metasurfaces for nonlinear frequency conversion [Invited][J]. Photonics Research, 2018, 6(5): 05000B82.