Large nonlinear optical absorption and refraction of β-In2Se3 thin film from above to below bandgap excitation

• DOI: 10.35848/1882-0786/ad4a1d
• Publication Date: 2024-05-11T02:14:28Z
• Authors: Dan Wu; Wen Dong; Yanqing Ge; Xueqin Cao; Mingjian Shi; Erkang Li; Nan Ma; Yixuan Zhou; Yuanyuan Huang; Chunhui Lu; Xinlong Xu
• Keywords: β-In2Se3; saturable absorption; Physics; QC1-999; self-defocusing; two-photon absorption; two dimensional materials

Abstract Nonlinear optical materials, especially two-dimensional materials, are anticipated to reveal broadband optical nonlinearity for future miniaturized photonic applications. Herein, we report a physical vapor deposition method to produce β-In2Se3 thin film and investigate the broadband nonlinear absorption (β) and refraction (n2) characteristics. The β-In2Se3 semiconductor shows an excellent optical nonlinearity with large β in 102 cm GW−1 scale and n2 in 10−12 cm2 W−1 scale from visible to NIR wavelengths, which are superior to those of metal carbides and nitrides (MXenes) and metal-organic frameworks. This excellent optical nonlinearity makes β-In2Se3 a promising candidate for advanced nanophotonic devices and beyond.