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Indexed by:Journal Papers

Date of Publication:2019-07-01

Journal:LASER & PHOTONICS REVIEWS

Included Journals:EI、SCIE

Volume:13

Issue:7

ISSN No.:1863-8880

Key Words:Fabry-Perot cavities; nonlinearity; phase changematerials; third-harmonic generation

Abstract:Third-order harmonic generation (THG) plays a vital role in microscopy, optical communications, etc. Conventional methods of obtaining efficient THG in macroscopic crystals is already mature; however, they will finally limit the miniaturization and integration of on-chip laser sources. To date, THG from either photonic crystals or metamaterials provides compact photonic platforms; however, selection of materials remains elusive. Herein, a giant enhancement of THG efficiency from an air/high index Ge2Sb2Te5 (GST)/gold multi-layered Fabry-Perot cavity is experimentally demonstrated. At cavity resonant wavelength in near-infrared regime, the efficiency of THG from a 50-nm thick amorphous GST planar film is boosted 422 times compared to that of nonresonant conditions. Interestingly, the THG efficiency has a dramatic decrease of three orders when the structural state of GST is transformed from amorphous to crystalline. These findings have a potential for achieving an ultracompact nonlinear optical source with high efficiency and switchable functionality.