Third-order nonlinear optical properties of Bi2S3 and Sb2S3 nanorods studied by the Z-scan technique

Bismuth sulfide (Bi₂S₃) and antimony sulfide (Sb₂S₃) nanorods were synthesized by hydrothermal method. The products were characterized by UV-vis spectrophotometer, X-ray powder diffraction (XRD) and transmission electron microscope (TEM). Bi₂S₃ and Sb₂S₃ nanorods were measured by Z-scan technique to investigate the third-order nonlinear optical (NLO) properties. The result of NLO measurements shows that the Bi₂S₃ and Sb₂S₃ nanorods have the behaviors of the third-order NLO properties of both NLO absorption and NLO refraction with self-focusing effects. The third-order NLO coefficient χ⁽³⁾ of the Bi₂S₃ and Sb₂S₃ nanorods are 6.25×10⁻¹¹ esu and 4.55×10⁻¹¹ esu, respectively. The Sb₂S₃ and Bi₂S₃ nanorods with large third-order NLO coefficient are promising materials for applications in optical devices.