Dissipative Soliton Resonance Region Research Articles

Dissipative-soliton-resonance and evolution in an all-normal dispersion Er-doped fiber laser

The generation of dissipative soliton resonance (DSR) in an all-normal dispersion erbium-doped fiber laser based on a real saturable absorber is amazing in both experiment and theory. However, it’s rarely to realize DSR in an all-normal Er-doped fiber laser in experiments to our knowledge. In this work, we analyze the principle of DSR generated in an all-normal dispersion erbium-doped fiber laser based on a real saturable absorber, and prove that the key reason is the reverse saturable absorption (RSA) effect of the real saturable absorber (SA). Then, we investigate the impacts of pump power, filter, and RSA coefficient in generating DSR pulse. In addition, when the saturable power of SA is above 25 W and the modulation depth of SA above 50%, a novel soliton explosion phenomenon based on RSA in DSR region is obtained for the first time to our knowledge. The work can be used for understanding the dissipative soliton resonance as well as the evolution in an all-normal dispersion Er-doped fiber laser. Furthermore, it also paves a way to realize high stable and high energy pulsed lasers in telecommunication region.

Multipulse dynamics under dissipative soliton resonance conditions.

The stable multipulse emission from an erbium-doped mode-locked fiber laser in dissipative soliton resonance (DSR) regime is numerically and experimentally investigated. It shows that in the multipulse operation of DSR, all pulses have identical characteristics. The number of these pulses is determined by the initial conditions, and keeps constant with the growth of pump power. Experimental results match well with the theoretical simulations. In the experiment, we obtain as high as 86 dual-wavelength DSR pulses, which have the same characteristics and are equally spaced in the cavity. Since the pulses behave similarly to harmonic mode-locking (HML), we call this phenomenon HML under DSR. By properly adjusting the polarization controllers, other numbers of multipulse emission in DSR region can be observed, which confirms that the number of DSR pulses depends on the initial conditions.

A long cavity passive mode-locking fibre laser with the reflective non-linear optical loop mirror

In this paper, we report a long cavity passively mode-locked fibre laser. The proposed mode locker is a reflective long cavity non-linear optical loop mirror (NOLM) which consists of a 50:50 coupler and 2-km single-mode fibres. The laser achieves stable mode locking at a fundamental repetition rate of 100 kHz. The rectangular pulses operating in dissipative soliton resonance region is generated in the laser. The relationship between the pulse duration and the pump power is investigated in detail. When the pump power is 200 mW, the laser generates rectangular pulses at 1565.57 nm (central wavelength) with pulse duration of 81.5 ns. The single pulse energy as high as 33.34 nJ is obtained. The results show that the reflective NOLM is an efficient mode locker and useful for the generation of high energy pulse.

Generation of microseconds-duration square pulses in a passively mode-locked fiber laser

An ultra-wide tunable square pulse operating in dissipative soliton resonance (DSR) region has been experimentally investigated in a passively mode-locked figure-of-eight fiber laser. In our experiment, by simply increasing the pump power, the pulse width can be tuned in an ultra-wide range from 135ns to 2272ns without wave-breaking while the peak power remains almost constant. The maximum output single pulse energy is 236.8nJ at the pump power of 508mW. A 960m highly nonlinear fiber (HNLF) is employed to realize widely tunable square pulse in the DSR region. To the best of our knowledge, this is the widest tunable range of pulse width in any all-fiber passively mode-locked fiber laser.

Dissipative Soliton Resonance in a Wavelength-Tunable Thulium-Doped Fiber Laser With Net-Normal Dispersion

We demonstrate an all-fiber figure-eight mode-locked thulium-doped fiber laser with a wide tunable range in both pulsewidth and wavelength. A 45-m-long ultrahigh numerical aperture fiber is used to manage the cavity dispersion, and the net cavity dispersion is calculated to be 0.8585 ps 2 at 1900 nm. With net-normal dispersion, the experimental laser, operating in a dissipative soliton resonance region, generates stable rectangular pulses. The pulsewidth varies from 480 ps to 6.19 ns with the increasing pump power, and its center wavelength has a 28.95-nm tunable range (from 1940.22 to 1969.17 nm) by properly adjusting the polarization controllers. The maximum of average output power and pulse energy is 60.73 mW and 19.51 nJ, respectively. The rectangular pulses have a clamped peak power of about 3.16 W. The wavelength-tunable fiber laser with high-energy output operating at 2 μm has great potential in various application fields.

High-Energy Square Pulses in a Mode-Locked Yb-Doped Fiber Laser Operating in DSR Region

We report the experimental observation of high-energy square pulses in all-normal-dispersion passively mode-locked Yb-doped fiber laser under dissipative soliton resonance (DSR) condition using a nonlinear polarization rotation technique. The generated square pulses are mode locked with fundamental cavity repetition rate of 1.86 MHz. The maximum output average power and the corresponding pulse energy are 62.1 mW and 34 nJ, respectively. The output square pulses are wave-breaking-free and can be tuned in pulsewidth from hundreds of picoseconds to several nanoseconds by changing the pump power. The multistability of DSR in all-normal-dispersion cavity has been first demonstrated in experiment, which is in agreement with theoretical prediction. The observed experimental results will enhance the understanding of fundamental physics of DSR phenomenon.

Highly Efficient Rectangular Pulse Emission in a Mode-Locked Fiber Laser

Dissipative soliton resonance (DSR) has been experimentally investigated in a nonlinear polarization rotation (NPR) mode-locked Yb-doped fiber laser with a long cavity. The adjustable nonlinear transmission function of the NPR and the relatively large nonlinearity of the long cavity play key roles in the formation of high energy rectangular pulses in the DSR region. The intracavity optical-to-optical efficiency can be as high as 46%, and the maximum pulse energy can reach 54.6 nJ with the relatively low pump power of 299 mW. This is so far the highest efficiency in a DSR laser operated at 1-µm wavelength yet achieved to our knowledge. Furthermore, while maintaining the pulse amplitude almost constant and without the appearance of wave-breaking phenomena, the pulse duration could be tuned from 54 to 91 ns by increasing only the pump power.

Wave-breaking-free pulse in an all-fiber normal-dispersion Yb-doped fiber laser under dissipative soliton resonance condition

We reported on the dissipative soliton resonance (DSR) phenomenon in a mode-locked Yb-doped fiber laser by using the nonlinear polarization rotation technique. It was found that the multi-pulse oscillation under high pump power could be circumvented by properly adjusting the polarization controllers, namely, the wave-breaking-free rectangular pulse in DSR region was achieved. As the DSR signature, the pulse duration varied from 8.8 ps to 22.92 ns with the increasing pump power. Correspondingly, the maximum pulse energy was 3.24 nJ. The results demonstrated that the DSR phenomenon could exist in Yb-doped fiber lasers, which could be used to achieve wave-breaking-free, ultrahigh-energy pulse.

Observation of Dissipative Soliton Resonance in a Net-Normal Dispersion Figure-of-Eight Fiber Laser

High-energy square pulses operating in dissipative soliton resonance region are experimentally observed in an erbium-doped figure-of-eight fiber laser with large net-normal dispersion for the first time to our knowledge. The dissipative soliton resonance is achieved by using the nonlinear-amplifying-loop-mirror mode-locked technique. The output pulse duration broadens linearly with the increase of pump power, while the peak power maintains a constant value. At the maximum pump power of 620 mW, the intracavity pulse energy is up to 379.2 nJ, and the average output power is 14.02 mW.

Dissipative soliton resonance in a passively mode-locked figure-eight fiber laser

The generation of mode-locked rectangular pulses operating in dissipative soliton resonance (DSR) region is demonstrated in an erbium-doped figure-eight fiber laser with net anomalous dispersion. The duration of the wave-breaking-free rectangular pulse broadens with the increase of pump power. At a maximum pump power of 341 mW, the pulse energy can be up to 3.25 nJ with a repetition rate of 3.54 MHz. Particularly, the spectrum of rectangular pulse operating in DSR exhibits conventional soliton sidebands. The observed results show that the formation of pulse operating in DSR region is independent of mode-locking techniques, which may be helpful for further understanding the DSR phenomenon.

Pulse dynamics of dissipative soliton resonance with large duration-tuning range in a fiber ring laser

The pulse dynamics operating in dissipative soliton resonance (DSR) region is experimentally investigated in a fiber ring laser. With the increase of pump power, the pulse profile transit from sech-like to rectangular shape was observed. The generated pulse in DSR region exhibits the conventional soliton spectrum with sideband generation. The duration-tuning range of the rectangular pulse is up to the cavity roundtrip time. Particularly, during the process of pulse duration broadening it was found that the rectangular pulse would trap a weak pulse generated from cw background. The obtained results may be useful for better understanding the DSR phenomenon.