1. Giant Third-Harmonic Optical Generation from Topological Insulator Heterostructures
- Author
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Chenhui Yan, Cheng Cen, Alan D. Bristow, Fan Shi, Tudor D. Stanescu, Yanjun Ma, Lian Li, Rishmali Sooriyagoda, and Yinxiao Xiang
- Subjects
Materials science ,business.industry ,Chalcogenide ,Mechanical Engineering ,Energy conversion efficiency ,Nonlinear optics ,Bioengineering ,Heterojunction ,02 engineering and technology ,General Chemistry ,Substrate (electronics) ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,chemistry.chemical_compound ,Reflection (mathematics) ,chemistry ,Topological insulator ,0103 physical sciences ,Topological sorting ,Optoelectronics ,General Materials Science ,010306 general physics ,0210 nano-technology ,business - Abstract
The downscaling of nonlinear optical devices is significantly hindered by the inherently weak nonlinearity in regular materials. Here, we report a giant third-harmonic generation discovered in epitaxial thin films of V-VI chalcogenide topological insulators. Using a tailored substrate and capping layer, a single reflection from a 13 nm film can produce a nonlinear conversion efficiency of nearly 0.01%, a performance that rivals micron-scale waveguides made from conventional materials or metasurfaces with far more complex structures. Such strong nonlinear optical emission, absent from the topologically trivial member in the same compound family, is found to be generated by the same bulk band characteristics that are responsible for producing the band inversion and the nontrivial topological ordering. This finding reveals the possibility of obtaining superior optical nonlinearity by examining the large pool of newly discovered topological materials with similar band characteristics.
- Published
- 2021