A High‐Index Ge2Sb2Te5‐Based Fabry–Perot Cavity and Its Application for Third‐Harmonic Generation. Issue 7 (19th June 2019)

• Record Type: Journal Article
• Authors: Cao, Tun; Liu, Kuan; Tang, Yutao; Deng, Junhong; Li, Kingfai; Li, Guixin
• Is Part Of: Laser & photonics reviews. Volume 13:Issue 7(2019)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2019-06-19
• Subjects: Fabry–Perot cavities -- nonlinearity -- phase change materials -- third‐harmonic generation; Lasers -- Periodicals; Photonics -- Periodicals; Lasers -- Périodiques; Photonique -- Périodiques; 621.36
• DOI: 10.1002/lpor.201900063
• Languages: English
• ISSNs: 1863-8880

Abstract

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 Ge2 Sb2 Te5 (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. Abstract : A giant enhancement of third‐harmonic generation (THG) efficiency from an air/Ge2 Sb2 Te5 (GST)/gold multi‐layered Fabry–Perot cavity is presented. Interestingly, the THG efficiency has a dramatic decrease of three orders when the structural state of GST transforms from amorphous to crystalline. These findings have a potential for achieving an ultracompact nonlinear optical source with high efficiency and switchable functionality.