Optical Properties of 2D 3R Phase Niobium Disulfide and Its Applications as a Saturable Absorber. Issue 4 (11th December 2019)

• Record Type: Journal Article
• Authors: Sun, Xiaoli; Shi, Bingnan; Wang, Haoyuan; Lin, Na; Liu, Shande; Yang, Kejian; Zhang, Baitao; He, Jingliang
• Is Part Of: Advanced optical materials. Volume 8:Issue 4(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2019-12-11
• Subjects: 3R‐NbS2 -- mode‐locked solid‐state bulk lasers -- optical properties -- saturable absorption -- 2D metal materials; Optical materials -- Periodicals; Photonics -- Periodicals; 620.11295
• DOI: 10.1002/adom.201901181
• Languages: English
• ISSNs: 2195-1071

Abstract

Abstract: 2D van der Waals metal 3R phase niobium disulfide (3R‐NbS2 ) has fascinating anisotropic, magnetic, optical, and superconducting properties. Herein, few‐layered 2D 3R‐NbS2 nanosheets are fabricated by combining liquid phase exfoliation and spin‐coating methods. The first principles calculations are performed to explore their electronic band structures to reveal the metallic properties and enhanced optical absorption as thickness increased. The linear and nonlinear optical properties arising from the plasmonic effects and nonequilibrium electrons are studied through the violet–visible–near‐infrared absorption spectroscopy, polarization‐resolved optical microscopy, and open‐aperture Z‐scan methods. The nonlinear absorption coefficient and imaginary part of the third‐order susceptibility are determined to be −2.5 × 10 6 cm GW −1 and −2.4 × 10 −6 esu at 1064 nm. Furthermore, 2D 3R‐NbS2 nanosheets based saturable absorbers are fabricated and applied in solid‐state pulsed lasers, in which a continuous‐wave mode‐locking laser operation at 1050.6 nm is demonstrated with a pulse duration of 302 fs. The results not only verify that 2D metallic materials, such as 3R‐NbS2, are excellent nonlinear optical modulators, but also will arouse a general interest in designing novel materials/structures with 2D metallic materials for electronic and photonic devices. Abstract : 3R phase NbS2 is a typical 2D metal. Its electronic band structure, linear, and nonlinear optical properties are systematically investigated, showing an excellent nonlinear saturable absorption behavior, which is introduced and enhanced by plasmonic effects and nonequilibrium carriers. Moreover, 2D 3R‐NbS2 nanosheets are successfully used as saturable absorbers for generating all‐solid‐state pulse lasers.