Solution-processed two-dimensional materials for ultrafast fiber lasers (invited)

Abstract Since graphene was first reported as a saturable absorber to achieve ultrafast pulses in fiber lasers, many other two-dimensional (2D) materials, such as topological insulators, transition metal dichalcogenides, black phosphorus, and MXenes, have been widely investigated in fiber lasers due to their broadband operation, ultrafast recovery time, and controllable modulation depth. Recently, solution-processing methods for the fabrication of 2D materials have attracted considerable interest due to their advantages of low cost, easy fabrication, and scalability. Here, we review the various solution-processed methods for the preparation of different 2D materials. Then, the applications and performance of solution-processing-based 2D materials in fiber lasers are discussed. Finally, a perspective of the solution-processed methods and 2D material-based saturable absorbers are presented

Few-layer MoS<inf>2</inf> saturable absorbers for short-pulse laser technology: Current status and future perspectives [Invited]

Few-layer molybdenum disul de (MoS2) is emerging as a promising quasi-two-dimensional material, further extending the library of suitable layered nanomaterials with exceptional optical properties for use in saturable absorber devices that enable short-pulse generation in laser systems. In this article, we catalog and review the nonlinear optical properties of few-layer MoS2, summarize recent progress in processing and integration into saturable absorber devices and comment on the current status and future perspectives of MoS2-based pulsed lasers.The authors would like to thank J. R. Taylor for fruitful discussions. EJRK and TH acknowledge support from the Royal Academy of Engineering (RAEng).This is the author accepted manuscript. The final version is available from OSA via https://www.osapublishing.org/prj/abstract.cfm?URI=prj-3-2-A30

Application of 2D Materials to Ultrashort Laser Pulse Generation

In recent years, novel two-dimensional (2D) materials have revolutionized the field of ultrafast laser technology. They have emerged as efficient, cost-effective, and universal saturable absorbers for the so-called ultrafast lasers, which emit ultrashort optical pulses (on the timescale of femtoseconds). Thanks to their unique optical properties, such as broadband absorption, short recovery time, low saturation fluence, and high modulation depth, they might be used as saturable absorbers for different lasers (solid state, fiber, semiconductor) operating at different wavelengths (ranging from 500 to 2500 nm). Such lasers may find various applications in different areas of industry, medical procedures, precise metrology, gas sensing, laser spectroscopy, etc. This chapter discusses the recent achievements in the area of ultrafast fiber lasers utilizing 2D materials: graphene, topological insulators (Bi2Te3, Bi2Se3, Sb2Te3), transition metal dichalcogenides (MoS2, WS2, etc.), and black phosphorus. The optical properties of those materials will be described. Their usability in ultrafast photonics will be discussed

Yb- and Er-doped fiber laser Q-switched with an optically uniform, broadband WS2 saturable absorber.

We demonstrate a ytterbium (Yb) and an erbium (Er)-doped fiber laser Q-switched by a solution processed, optically uniform, few-layer tungsten disulfide saturable absorber (WS2-SA). Nonlinear optical absorption of the WS2-SA in the sub-bandgap region, attributed to the edge-induced states, is characterized by 3.1% and 4.9% modulation depths with 1.38 and 3.83 MW/cm(2) saturation intensities at 1030 and 1558 nm, respectively. By integrating the optically uniform WS2-SA in the Yb- and Er-doped laser cavities, we obtain self-starting Q-switched pulses with microsecond duration and kilohertz repetition rates at 1030 and 1558 nm. Our work demonstrates broadband sub-bandgap saturable absorption of a single, solution processed WS2-SA, providing new potential efficacy for WS2 in ultrafast photonic applications.The authors thank E. J. R. Kelleher for valuable discussions. MZ acknowledges support from Beihang University, China, through a Zhuoyue Bairen Program and TH from the Royal Academy of Engineering through a fellowship (Graphlex). This work at Beihang University was supported by 973 Program (2012CB315601), NSFC (61221061/61435002) and the Fundamental Research Funds for the Central Universities.This is the final version of the article. It was first available from NPG via http://dx.doi.org/10.1038/srep1748

Recent research and advances of material-based saturable absorber in mode-locked fiber laser

The incorporation of the material-based saturable absorber (SA) to generate mode-locked fiber laser (MLFL) has been extensively explored and demonstrated. However, the material-based SAs have some challenges in terms of optical damage threshold, design complexity, robustness, and stability due to several factors. Presently, several works have been demonstrated to address material-based SA fabrication issues. Therefore, this paper aims to comprehensively review the pros and cons of material-based SA in terms of material synthesis techniques, material characteristics, material-polymer composite, SA structure, and deposition techniques, along with current issues and challenges, and conclude with concrete recommendations. All the highlighted insights of this review will contribute to the increased efforts toward the development of the material-based SAs for the MLFL.Peer reviewe