Open AccessUltrafast saturable absorption in topological insulator Bi_2SeTe_2 nanosheets
Author(s) -
Hang Zhang,
Xin He,
Wei Lin,
Rongfei Wei,
Fangteng Zhang,
Xi Du,
Guoping Dong,
Jianrong Qiu
Publication year - 2015
Publication title -
optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.23.013376
Subject(s) - topological insulator , ultrashort pulse , materials science , saturable absorption , optics , scattering , saturation (graph theory) , absorption (acoustics) , insulator (electricity) , optoelectronics , laser , fiber laser , physics , condensed matter physics , wavelength , mathematics , combinatorics , composite material
Topological insulator (TI) Bi2SeTe2 nanosheets with very regular hexagonal morphology were synthesized by a hydrothermal route. Open aperture (OA) z-scan method was performed to measure the saturable absorption (SA) characteristics of the as-prepared TI Bi2SeTe2 nanosheets. The measured modulation depth, saturation intensity and nonsaturable loss of the sample were 61.9%, 4.46 GW/cm2 and 4.5% respectively. An ultrafast intraband scattering time of ~50 fs was obtained through simulating the SA curve, which indicates the TI Bi2SeTe2 nanosheets may be a good candidate for mode-locking material.