Yichang Meng

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.

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.

Widely tunable, narrow line width and low optical noise continuous-wave all fiber Er:Yb co-doped double-clad ring laser

In this paper, we report a widely tunable, narrow linewidth, low noise continuous-wave double-clad Er:Yb doped fiber ring laser. Tunability is demonstrated in wide range spanning from 1520 to almost 1620 nm covering the C and L spectral bands. The cavity design is optimized in order to achieve the largest tuning range with very high optical signal-to-noise ratio (SNR). The output coupling ratio greatly influences the tuning range of the laser while the position of the spectral filter determines the SNR. The obtained laser exhibits a tuning range over 98 nm with a nearly constant SNR of about 58.5 dB.

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.

Graphene-based saturable absorber for high average-power fiber lasers

Owing to its strong optical characteristics, graphene has emerged in the field of ultrafast lasers as a prominent saturable absorber. In this communication, we present a passively mode-locked Er:Yb doped double-clad fiber laser using a graphene deposited tapered fiber (GDTF). Averaging 20 μm of diameter with a length of 6 mm, the taper enables a strong light–graphene interaction owing to the evanescent field of the excited cladding mode. To create the saturable absorber device, graphene solution is carefully deposited via a micro syringe so that the waist of the taper is completely immersed into the aqueous solution. Then, a continuous wave laser with output power up to 95-mW centered at 1550 nm is injected into the taper. Deposition of graphene onto the taper by the optical tweezers effect started when the transmitted power dropped significantly. Afterwards, the GDTF is implemented in a fiber cavity to test its mode-locking performance. At the maximum available pump power, we obtain the 326th harmonic mode locking of soliton bunches with average output power of 520 mW.

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.

High energy square-wave generation from an Er:Yb passive mode-locked fiber ring laser

Based on the dissipative soliton resonance occurring in highly anomalous dispersion regime, we have demonstrated the emission of highly energetic square-wave pulses from the Er:Yb doped double clad fiber laser passively mode-locked through nonlinear polarization evolution. In contrast with the classical soliton regime, when the pumping power increases the pulse broadens and its energy increases, both linearly. Experimental results exhibit a stable mode-locking with single pulse energy as high as 2.27 μJ, a pulse duration of about 200 ns and an average output power of 850 mW.

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.