Nonlinear optical properties of tin telluride topological crystalline insulator at a telecommunication wavelength

• Published in: Journal of alloys and compounds 2022-12, Vol.925, p.166643, Article 166643
• Main Authors: Lee, Kyungtaek, Jhon, Young In, Kwon, Suh-young, Lim, Geunweon, Kim, Jeehwan, Lee, Ju Han
• Format: Article
• Language: English
• Subjects: Absorptivity; Crystal structure; Crystallinity; Electron spin; Femtosecond pulsed lasers; Fiber lasers; Insulators; Magnetic properties; Nonlinear optical materials; Nonlinear optical properties; Nonlinear optics; Optical properties; Photonic crystals; Quantum dots; Refractivity; Saturable absorption; Spin-orbit interactions; Tin tellurides; Topological crystalline insulators; Topology; Two dimensional materials
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2022.166643

Topological crystalline insulators (TCIs) have a new topological state where topological nature comes from crystal symmetries without necessitating spin-orbit coupling. Their superb electronic, magnetic, and superconducting properties have intensively been studied. Despite great potential, however, their nonlinear optical properties are rarely examined. For the first time, this study investigates the nonlinear refraction and absorption properties of SnTe TCIs using the Z-scan techniques. A high nonlinear refractive index of -0.111 ± 0.004 cm2/GW and a nonlinear absorption coefficient of -(2.02 ± 0.135)× 103 cm/GW are obtained from SnTe TCIs at the commercially important telecommunication wavelength, being superior and/or comparable to two dimensional (2D) materials and/or renowned photonic crystals. Ab-initio simulations show that SnTe TCIs are suitable for ultrabroad-band application and mechanically stable at high thermal conditions. Lastly, we demonstrate that 1550 nm mode-locked femtosecond lasers can readily be achieved by exploiting the conspicuous nonlinear optical absorption of SnTe TCIs without using any nano-engineered ones like quantum dots. This study strongly indicates a promising potential of SnTe TCIs in a wide range of nonlinear optics, opening an avenue toward advanced TCIs-based photonic technologies. •Optical nonlinearity of topological crystalline insulators (TCIs) is revealed.•It is superior and/or comparable to renowned 2D materials and photonic crystals.•TCIs have excellent ultrabroadband applicability due to Weyl semimetal states.•TCIs can produce femtosecond pulses via mode-locking without any nanoengineering.