Alioune Niang

1.61 μm high-order passive harmonic mode locking in a fiber laser based on graphene saturable absorber.

We demonstrate a passive mode-locked Er:Yb doped double-clad ring fiber laser based on graphene saturable absorber. By adjusting the polarization controller and minimizing the cavity loss, the laser can operate at hundreds of harmonics of the fundamental repetition frequency of the resonator with the central wavelength of 1.61 μm. Up to 683rd harmonic (which corresponds to 5.882 GHz) of the fundamental repetition frequency was achieved.

Passive harmonic mode locking of soliton crystals

We report experimental observation of passive harmonic mode locking (HML) in which the basic pattern is a soliton crystal. Several crystal states were generated from an initial large bound state by increasing the pump power. The soliton crystals are identical and progressively span along the cavity to finally take a regular spacing leading to HML of solitons crystal.

1.6 μm emission based on linear loss control in a Er:Yb doped double-clad fiber laser

Based on the control of the linear losses of the cavity, we demonstrate the possibility to achieve filterless laser emission above 1.6 μm, from a C-band double-clad Er:Yb doped fiber amplifier. The concept is validated in both continuous wave and mode-locked regimes, using a figure-of-eight geometry. A unidirectional ring cavity is also tested in the continuous regime. Spectral properties of laser emissions are characterized as a function of the intracavity linear losses.

High power L-band mode-locked fiber laser based on topological insulator saturable absorber

We demonstrate a passive mode-locked Er:Yb doped double-clad fiber laser using a microfiber-based topological insulator (Bi(2)Se(3)) saturable absorber (TISA). By optimizing the cavity loss and output coupling ratio, the mode-locked fiber laser can operate in L-band with high average output power. With the highest pump power of 5 W, 91st harmonic mode locking of soliton bunches with average output power of 308 mW was obtained. This is the first report that the TISA based erbium-doped fiber laser operating above 1.6 μm and is also the highest output power yet reported in TISA based passive mode-locked fiber laser.

High power passively mode-locked fiber laser based on graphene nanocoated optical taper

We experimentally demonstrate a passively mode-locked Er:Yb doped double-clad fiber laser using a graphene nanocoated optical taper. Averaging 20 μm of clad diameter with a length of 6 mm, such a saturable absorber enables a strong light–graphene interaction owing to the evanescent field of the excited cladding mode. With the highest pump power of 5 W, the 326th harmonic mode locking of soliton bunches with an average output power of 520 mW was obtained in a fiber ring cavity that has a fundamental frequency of 1.67 MHz. This is the highest average output power yet reported in graphene-based passively mode-locked fiber lasers.

High power passive mode-locked L-band fiber laser based on microfiber topological insulator saturable absorber

In this communication, we demonstrate a passive mode-locked Er:Yb co-doped double-clad fiber laser using a tapered microfiber topological insulator (Bi2Se3) saturable absorber (TISA). The topological insulator is drop-casted onto the tapered fiber and optically deposited by optical tweezer effect. We use a ring laser setup including the fabricated TISA. By carefully optimizing the cavity losses and output coupling ratio, the mode-locked laser can operate in L-band with a high average output power. At a maximum pump power of 5 W, we obtain the 91st harmonic mode-locking of soliton bunches with a 3dB spectral bandwidth of 1.06nm, a repetition rate of 640.9 MHz and an average output power of 308mW. As far as we know, this is the highest output power yet reported of a mode-locked fiber laser operating with a TISA.

Dissipative soliton resonance in the Er:Yb:doped double-clad fiber laser

Dissipative soliton resonance (DSR) is an efficient way to achieve high energetic pulses without wave breaking. In fiber laser, DSR operation manifests as square pulses emission. Based on this principle, we have experimentally demonstrated pulses in the micro joule range. Experiments have been conducted using double-clad Er:Yb-doped fiber lasers in different optical configurations. In particular, we demonstrate 10 μJ DSR emission in an optimized cavity and also the possibility to observe wave breaking in DSR regime. In the latter case, harmonic mode-locking of square pulses is demonstrated.

Exhaustive study of dissipative soliton resonance in a dual amplifier passively mode-locked fiber laser

We have proposed an exhaustive experimental study of dissipative soliton resonance in a double clad Er:Yb co-doped dual amplifier passively mode-locked figure-of-eight fiber laser. By adjusting the pumping powers of the amplifiers, both the amplitude and width of the output square-wave pulse can be tuned continuously. Moreover, some other key parameters such as the net cavity dispersion and the coupling ratio between the two loops of the cavity have been studied.

Dynamics of dissipative soliton resonance square pulses in fiber lasers

In this article, we experimentally investigate the dynamics of dissipative soliton resonance (DSR) square pulses in different all-anomalous passively mode-locked double-clad Er:Yb fiber laser setups. In the figure-of-eight configuration, the aim of employing an amplifier in each loop is to control the output pulses amplitude and width, which depend on the pumping power. At a maximum total pumping power of 4.7 W and a fundamental frequency of 133 kHz, 10 µJ DSR square pulses with a signal-to-noise ratio of 60 dB, are generated without observing any wave-breaking. In the fiber ring configuration, by fixing the pumping power to 1.18 W and carefully adjusting the polarization controllers, we obtain a DSR square pulse that can be split in a series of equally spaced smaller square pulses up to the 4th harmonic order at a fundamental frequency of 672 kHz.

1.6 µm laser emission from the Er:Yb doped double-clad fiber amplifier

In this paper, we demonstrate the possibility to obtain laser emission above 1.6 μm from a C-band Er:Yb doped fiber amplifier thanks to the control of linear losses of the cavity. The principle is validated in figure-of-eight fiber laser. This concept is then successfully used to realize a widely tunable graphene-based mode-locked fiber laser.