CHIN. PHYS. LETT. Vol. 31, No. 4 (2014) 044205
Wavelength-Tunable Rectangular Pulse Dissipative Soliton Operation of an
Erbium-Doped Mode-Locked Fiber Laser
*
HU Xue-Juan(胡学娟), GUO Chun-Yu(郭春雨), RUAN Shuang-Chen(阮双琛)
**
Shenzhen Key Laboratory of Laser Engineering, Key Laboratory of Advanced Optical Precision Manufacturing
Technology of Guangdong Higher Education Institutes, College of Electronic Science and Technology,
Shenzhen University, Shenzhen 518060
(Received 24 December 2013)
The wavelength-tunable rectangular pulse dissipative soliton (DS) is experimentally demonstrated, for the first
time to the best of our knowledge, in an erbium-doped figure-of-eight fiber laser based on the nonlinear amplifying
loop mirror mode-locked technique. The proposed rectangular pulse DS fiber laser can operate in the wavelength-
tunable mode-locked state from 1573.5 nm to 1594.6 nm with the rotation of the polarization controllers. The
achieved output wavelengths are 1573.5 nm, 1576.3 nm, 1586.8 nm, 1590.4 nm and 1594.6 nm, respectively. The
pulse widths of the rectangular pulse can also be tuned from ∼8 ns to ∼24 ns by adjusting the pump power.
The fundamental repetition rate of the rectangular pulse DS is 1.154 MHz and the output power is 6.14 mW (at
1594.6 nm).
PACS: 42.55.Wd, 42.60.Fc, 42.81.Dp DOI: 10.1088/0256-307X/31/4/044205
The compact-size and high-stability passively
mode-locked fiber lasers have drawn great atten-
tion for their significant applications in spectroscopy,
nonlinear optics, and biomedical research.
[1,2]
Var-
ious approaches, including semiconductor saturable
absorber mirror (SESAM),
[3]
nonlinear amplifying
loop mirror (NALM),
[4]
nonlinear polarization rota-
tion (NPR),
[5]
carbon nanotube,
[6]
and atomic layer
graphene,
[7]
have been proposed to achieve passively
mode-locked pulses. In the past decades, different
kinds of mode-locked fiber lasers, such as conventional
soliton lasers,
[8,9]
stretched pulse lasers,
[5,10]
and self-
similar pulse lasers
[11,12]
have been obtained. Re-
cently, the dissipative soliton (DS) mode-locked fiber
lasers have been investigated extensively for their ex-
cellent performance at high-energy pulse generation.
The formation of the DS is caused by the inter-
play between the laser gain and loss, cavity dispersion,
and fiber nonlinear effect. Two kinds of typical opera-
tions, that is, the Gaussian DS
[13−15]
and the rectan-
gular DS,
[16,17]
have been observed. The Gaussian DS
mode-locked fiber laser exhibits a Gaussian pulse with
steep spectral edges. In 2010, Im et al.
[18]
reported
an erbium-doped Gaussian DS mode-locked fiber laser
at a large net normal dispersion cavity by employing
a single-walled carbon nanotube saturable absorber.
The Gaussian DS mode-locked fiber laser operating
at the wavelength of 1.0 µm was also achieved by us-
ing atomic multilayer graphene.
[15]
Moreover, the rect-
angular pulse DS mode-locked fiber lasers have also
been demonstrated. The rectangular pulse DS have
been achieved in fiber ring lasers by using the NPR
mode-locked technique.
[19,20]
The NALM mode-locked
technique was also utilized to achieve the rectangular
pulse DS in figure-of-eight fiber lasers with net normal
dispersion
[21]
and anomalous dispersion.
[22]
In addition, the wavelength tuning of the mode-
locked fiber lasers have attracted much attention
for their versatile applications, such as wavelength-
division-multiplexed (WDM) communication sys-
tems, optical components testing, and optical fiber
sensing.
[23,24]
Consequently, wavelength-tunable DS
fiber lasers are thought to be more attractive for a
combination of high pulse energy and wavelength tun-
ability. Zhang et al.
[25]
experimentally developed a
wavelength-tunable erbium-doped Gaussian DS fiber
laser with atomic layer graphene as the mode locker.
The wavelength can be tunable in a wide range from
1570 nm to 1600 nm. Zhang et al.
[26]
reported the
all-fiber tunable Gaussian DS operation in an all-
normal-dispersion Yb-doped fiber laser by using a
single mode-multimode-single mode filter. Although
the wavelength-tunable Gaussian DS operations have
been achieved in both the erbium-doped and the Yb-
doped fiber lasers, the wavelength-tunable rectangular
pulse DS mode-locked fiber laser has not been demon-
strated so far.
In this Letter, we achieve the wavelength-tunable
rectangular pulse DS in an erbium-doped mode-locked
fiber laser. The NALM technique is employed as an
*
Supported by the National Natural Science Foundation of China under Grant Nos 61275144 and 61308049, the PhD Start-up
Fund of Natural Science Foundation of Guangdong Province under Grant No S2013040012496, the Science and Technology Project
of Shenzhen City under Grant Nos JCYJ20120613110637373 and JCYJ20130329142022715, the Improvement and Development
Project of Shenzhen Key Lab under Grant No ZDSY20120612094924467, and the Natural Science Foundation of Shenzhen University
under Grant No 201203.
**
Corresponding author. Email: scruan@szu.edu.cn
© 2014 Chinese Physical Society and IOP Publishing Ltd
044205-1