Observation of chaotic polarization attractors from a
graphene mode locked soliton fiber laser
Chang Zhao (赵 畅)
1
, Qianqian Huang (黄千千)
1
, Mohammed Al Araimi
2
,
Aleksey Rozhin
3
, Sergey Sergeyev
3
, and Chengbo Mou (牟成博)
1,
*
1
Key Laboratory of Specialty Fiber Optics and Optical Access Networks, Shanghai Institute for Advanced
Communication and Data Science, Joint International Research Laboratory of Specialty Fiber Optics and Advanced
Communication, Shanghai University, Shanghai 200444, China
2
Higher College of Technology, Al-Khuwair 133, Sultanate of Oman
3
Aston Institute of Photonic Technologies (AIPT), Aston University, Birmingham B4 7ET, UK
*Corresponding author: mouc1@shu.edu.cn
Received December 3, 2018; accepted December 27, 2018; posted online January 29, 2019
We have demonstrated an all-fiber passively mode locked erbium-doped fiber laser (EDFL) based on
graphene–polyvinyl-alcohol film. By watchfully adjusting the polarization controller, two different polarization
attractors, including polarization locked vector solitons and a circular attractor, can be observed. This is first
time, to the best of our knowledge, to explore the dynamics polarization attractors exhibited by a vector soliton
generated from an EDFL based on graphene.
OCIS codes: 260.5430, 140.3510.
doi: 10.3788/COL201917.020012.
Vector solitons (VSs) have been extensively studied since
the propagation of optical pulses in birefringent fibers
was theoretically analyzed in 1987
[1]
. Soon afterwards,
VSs were investigated and defined by Christodoulides et al.
in birefringent nonlinear dispersive media for the first
time
[2]
, to the best of our knowledge. A VS is a type of
stable-state wave containing two orthogonal polarization
components that keep polarization fixed or periodic evolu-
tion when propagating in a single mode fiber (SMF) that
holds birefringence. Consequently, an SMF can be expected
as an ideal vehicle to propagate VSs as a result of the
weak birefringence. It is well known that fiber lasers have
the ability to generate VSs, utilizing physical saturable
absorbers (SAs) such as semiconductor saturable absorption
mirrors (SESAMs), carbon nanotube (CNT), and graphene.
Besides, in recent years some new two-dimensional (2D)
materials, such as black phosphorus
[3,4]
,MXene
[5]
,and
bismuthene
[6]
, have been reported to serve as excellent SAs.
Due to the nonlinear coupling between the two orthogo-
nal polarization components, various types of VSs can be
formed in the laser cavity. In polarization locked VSs
(PLVSs), the state of polarization (SOP) and phase
velocity are fixed
[7,8]
, while group velocity locked VSs
(GVLVSs) require group velocity locking and no demand
for phase velocity locking
[9]
. Besides, some periodical
propagating VSs can be locked to the cavity roundtrip
time or its multiples, which are commonly referred as
polarization rotation VSs (PRVSs)
[10,11]
. Some researchers
have reported the observation of the vector nature of
various dynamic patterns based on figure-eight fiber
lasers
[12,13]
. In the past decade, VSs in passively mode
locked fiber lasers using nanomaterial-based SAs have
been extensively studied. For instance, polarization
dynamics of VSs in the cavity utilizing CNTs have been
systematically explored
[14–18]
. Besides, the iconic 2D
material, such as graphene, possesses not only amazing elec-
tronic properties but also fantastic optical properties with
the potential of operating in a wideband range as a novel
SA
[19,20]
. SAs based on graphene also feature polarization
independent saturable absorption
[21]
. Therefore, for fiber
lasers using graphene, intensive investigations have been
carried out to study various polarization dynamic patterns
and the interaction between two orthogonal polarization
components of VSs using a polarization beam splitter
(PBS)
[19,21–24]
. Nevertheless, among all the studies, the phase
difference between two orthogonal polarization compo-
nents and degree of polarization (DOP) are not identified,
which can actually be measured with a commercial polar-
imeter. The missing phase information resulting from the
polarization resolved spectral analysis using a PBS may
lead to an ambiguous explanation of VSs. Moreover, the
tendency of evolution of VSs at a slow time scale from a
small number to thousands of roundtrips is defined as
asymptotic states (attractors), which could not be resolved
by a PBS
[15]
. A more comprehensive interpretation of the
dynamic evolution of VSs is therefore necessary.
In this work, we report the polarization attractors for the
first time, to the best of our knowledge, exhibited by VSs
operation of an erbium-doped fiber laser (EDFL) based on
a graphene–polyvinyl-alcohol (PVA) SA. We have experi-
mentally shown two types of polarization attractors with
the single pulse regime. The radio frequency (RF) spectrum
indicates ∼40 dB signal to noise ratio (SNR) at the funda-
mental frequency. The demonstrated laser may find appli-
cations in secure communication
[25]
, manipulation of atoms
and nanoparticles
[26–28]
, and control of magnetization
[29]
.
Figure
1 shows the typical setup of a graphene-based
passively mode locked EDFL. The total cavity length is
COL 17(2), 020012(2019) CHINESE OPTICS LETTERS February 10, 2019
1671-7694/2019/020012(5) 020012-1 © 2019 Chinese Optics Letters