Recent Advances of 2D Materials in Nonlinear Photonics and Fiber Lasers

Abstract

The explosive success of graphene opens a new era of ultrathin 2D materials. It has been realized that the van der Waals layered materials with atomic and less atomic thickness can not only exist stably, but also exhibit unique and technically useful properties including small size effect, surface effect, macro quantum tunnel effect, and quantum effect. With the extensive research and revealing of the basic optical properties and new photophysical properties of 2D materials, a series of potential applications in optical devices have been continuously demonstrated and realized, which immediately roused an upsurge of study in the academic circle. Therefore, the application of 2D materials as broadband, efficient, convenient, and versatile saturable absorbers in ultrafast lasers is a potential and promising field. Herein, the main preparation methods of 2D materials are reviewed and technical guidelines for identifying and characterizing layered 2D materials are provided. After investigating the characteristics of 2D materials thoroughly in nonlinear optics, their performances in fiber lasers are comprehensively summarized according to the types of materials. Finally, some developmental challenges, potential prospects, and future research directions are summarized and presented for such promising materials.

Thickness-Dependent Optical Nonlinearities of Nanometer-Thick Sb2Te3 Thin Films: Implications for Mode-Locking and Super-resolved Direct Laser Writing

“…The real part of the third order nonlinear optical susceptibility has been then obtained by means of the following equation: (4) where c is the speed of light in cm s -1 and has to be given in cm 2 W -1 .…”

“…[1][2][3][4][5][6][7][8][9][10][11][12][13] Several 2D materials exhibit unique optical and nonlinear optical (NLO) properties which are mainly due to their topological insulating characters. 4,14 More specifically, these materials have an insulating character in the bulk, while conducting states appear at the surface. This results to a band structure which is similar to that of graphene, showing a Dirac-like linear band dispersion.…”

Palladium diselenide as a direct absorption saturable absorber for ultrafast mode-locked operations: from all anomalous dispersion to all normal dispersion

“…Ultrafast mode-locked fiber lasers have been widely investigated owing to their extensive applications in communication, biophotonics, photochemistry and so on [1][2][3][4]. Hitherto, active and passive mode-locked technologies have been widely employed to achieve ultrafast modelocked operations.…”

In-plane anisotropic third-harmonic generation from germanium arsenide thin flakes

“…In addition, the broad optical spectral range covered by 2D materials make them very promising for photonic and optoelectronic applications 17 . Besides the linear optical properties, 2D materials exhibit strong optical nonlinearities which endows them as promising nonlinear optical materials 10 , 18 , 19 which have been used for saturable absorption (SA) 20 , second-harmonic generation (SHG) 21 , THG 22 , 23 , self-phase modulation 24 , 25 , nonlinear Kerr effect 26 , 27 and four-wave mixing (FWM) 28 . Beyond graphene, 2D transition metal dichalcogenides (TMDs) such as MoS 2 21 , 29 – 31 and WSe 2 32 , 33 , hexagonal boron nitride (h-BN) 21 , and other kinds of materials such as ReS 2 34 , 35 and GaSe 36 have shown strong SHG and THG responses.…”