Direct observation of an irradiance dependent nonlinear refraction in CVD single layer graphene

OPTICS COMMUNICATIONS

卷:481

Article

Demetriou, G.¹  Biancalana, F.¹  Abraham, E.²  Ji, W.³  Wang, Y.⁴  Kar, A. K.¹ 

[1] Heriot Watt Univ, Sch Engn & Phys Sci, Inst Photon & Quantum Sci, David Brewster, Edinburgh EH14 4AS, Midlothian, Scotland

[2] Heriot Watt Univ, Sch Engn & Phys Sci, Inst Biol Chem Biophys & Bioengn, David Brewster Bldg, Edinburgh EH14 4AS, Midlothian, Scotland

[3] Natl Univ Singapore, Dept Phys, 2 Sci Dr 3, Singapore 117542, Singapore

[4] Chinese Acad Sci, Inst Proc Engn, State Key Lab Multiphase Complex Syst, Beijing 100190, Peoples R China

关键词: Graphene;    Nonlinear optical materials;    Ultrafast nonlinear optics;    Nonlinear refraction;   

DOI  :  10.1016/j.optcom.2020.126535

来源: Elsevier

【 摘 要 】

The nonlinear optical properties of single layer graphene are studied via Z-scan. The measurements are carried out at 1045 nm with a 360 femtosecond highly stable Yb doped mode-locked fiber laser. Under laser illumination single-layer graphene exhibits both a transmittance increase due to saturable absorption and a nonlinear phase-shift due to nonlinear refraction. The nonlinear refraction measurements were carried out from 0.5 to 8 GW/cm(2) revealing an expected irradiance-dependent nonlinear refraction. An effective nonlinear refractive index coefficient (n) over tilde (I) is used to describe this and discriminate it from the conventional n(2) coefficient usually measured by Z-scan. The saturation level of the nonlinear phase-shift where the nonlinear response becomes irradiance dependent is deduced from the experimental data.

【 授权许可】

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