Two-dimensional tin diselenide nanosheets
pretreated with an alkaloid for near- and
mid-infrared ultrafast photonics
ZHENHONG WANG,
1,†
BIN ZHANG,
1,†
BING HU,
1
ZHONGJUN LI,
1
CHUNYANG MA,
1
YU CHEN,
1
YUFENG SONG,
1
HAN ZHANG,
1
JUN LIU,
1,
* AND GUOHUI NIE
1,2
1
Shenzhen Engineering Laboratory of Phosphorene and Optoelectronics; Institute of Translational Medicine, Department of Otolaryngology,
Shenzhen Second People’s Hospital, The First Affiliated Hospital of Shenzhen University, Health Science Center; International Collaborative
Laboratory of 2D Materials for Optoelectronics Science and Technology of Ministry of Education, College of Physics and Optoelectronic
Engineering, Shenzhen University, Shenzhen 518060, China
2
e-mail: nghui@21cn.com
*Corresponding author: liu-jun-1987@live.cn
Received 21 May 2020; revised 12 August 2020; accepted 9 September 2020; posted 11 September 2020 (Doc. ID 398203);
published 12 October 2020
Two-dimensional (2D) tin diselenide (SnSe
2
), a novel layered material with excellent optical and electronic prop-
erties, has been extensively investigated in various promising applications, including photodetectors, optical
switching, and ultrafast photonics. In this work, SnSe
2
nanosheets have been obtained after pretreatment in
an alkaloid, exhibiting high optical absorption and electron-enriched properties. Besides, the performances of
the prepared SnSe
2
in near-infrared (NIR) and mid-in frared (MIR) ultrafast photonics are presented.
Notably, by employing the SnSe
2
-deposited microfiber device as a saturable absorber (SA) exhibiting typical
nonlinear optical absorption properties, stable ultrashort pulses and rogue waves are realized in an erbium-doped
fiber laser. Furthermore, the SnSe
2
-deposited SA device is also applied to a thulium-doped fiber laser to achieve
stable ultrashort pulses. This study indicates that SnSe
2
is expected to be a suitable candidate for ultrafast fiber
lasers in the NIR and MIR regions.
© 2020 Chinese Laser Press
https://doi.org/10.1364/PRJ.398203
1. INTRODUCTION
2D materials have extensively ser ved as promising materials
for optoelectronic fields such as photodetectors [1], optical
switches [2], optical modulators [3,4], and saturable absorbers
(SAs) [5–7]. The family of 2D materials that have been widely
demonstrated recently due to their promising potential in ultra-
fast photonics, include graphene, graphdiyne, black phospho-
rus (BP), MXene, topological insulators (TIs), and transition
metal dichalcogenides (TMDs). Recently, as a kind of typical
TMD, SnSe
2
has attracted considerable research interest
because of its excellent electrical and optical properties.
Besides, SnSe
2
possesses a direct band gap from 1.84 to
2.04 eV and an indirect band gap from 1.07 to 1.69 eV based
on its layered-sensitive features [8]. In addition, SnSe
2
exhibits
excellent nonlinear optical properties (NOPs), which can be
used as promising SAs in the broadband regions [9–14].
However, only Q-switched operation has been successfully
demonstrated using the SnSe
2
SA in the 2 μm mid-infrared
(MIR) region. Therefore, it is imperative and significant to fur-
ther investigate the nonlinear optical properties of the new 2D
material SnSe
2
and its application in ultrafast photonics in the
near-infrared (NIR) and MIR wavelength regions.
Ultrafast fiber lasers have been widely used in industries and
scientific research fields [15,16] and have generated enormous
economic and social benefits. The passive mode-locking tech-
nique using 2D materials as SAs is generally considered one of
the most efficient approaches to obtain ultrashort pulses in ul-
trafast fiber lasers. At present, the majority of mode-locked fiber
lasers based on 2D material SAs are concentrated on ultrashort
pulse generation in the NIR range (1–1.5 μm). It is interesting
to note that the ultrafast pulse fiber lasers operating in the MIR
region (2–3.5 μm) have exhibited potential applications such as
optical communication [17], supercontinuum generation [18],
and laser radar [19]. Therefore, it is essential to explore and
investigate the available 2D materials with unique nonlinear
absorption features in the MIR region. In addition, ultrafast
fiber lasers are the ideal platform for studying soliton dynamics
[20–22]. At present, there are multiple types of soliton phe-
nomena reported in ultrafast fiber lasers, including soliton ex-
plosion [23], soliton pulsation [24], soliton molecules [25], and
Research Article
Vol. 8, No. 11 / November 2020 / Photonics Research 1687
2327-9125/20/111687-10 Journal © 2020 Chinese Laser Press