Handing Xia

Ultrafast erbium-doped fiber laser mode-locked by a CVD-grown molybdenum disulfide (MoS2) saturable absorber.

We demonstrate an erbium-doped fiber laser passively mode-locked by a multilayer molybdenum disulfide (MoS(2)) saturable absorber (SA). The multilayer MoS(2) is prepared by the chemical vapor deposition (CVD) method and transferred onto the end-face of a fiber connector. Taking advantage of the excellent saturable absorption of the fabricated MoS(2)-based SA, stable mode locking is obtained at a pump threshold of 31 mW. Resultant output soliton pulses have central wavelength, spectral width, pulse duration, and repetition rate of 1568.9 nm, 2.6 nm, 1.28 ps, and 8.288 MHz, respectively. The experimental results show that multilayer MoS(2) is a promising material for ultrafast laser systems.

Passively

We demonstrate a passively Q-switched erbium-doped fiber laser (EDFL) based on few-layer MoS₂ as a saturable absorber (SA). Few-layer MoS₂ is prepared by the chemical vapor deposition method. The prepared MoS₂ is transferred onto the end face of a fiber connector to form a fiber-compatible MoS₂-based SA. The saturation intensity and modulation depth of the MoS₂ SA are measured to be 0.43 MW/cm² and 33.2%, respectively. The Q-switched EDFL has an all-fiber linear cavity with two fiber Bragg gratings as the end mirrors. By inserting the MoS₂ SA into the laser cavity, stable Q-switched operation is achieved at 1.55 μm. The laser has a pump threshold of 20.4 mW, a pulse repetition rate tunable from 10.6 to 173.1 kHz, and a minimum pulse duration of 1.66 μs. Our results show that few-layer MoS₂ is a promising SA for Q-switching laser operation.

Q

We report on supercontinuum generation in a highly nonlinear fiber (HNLF) pumped by noise-like pulses (NLPs) emitted from a compact fiber ring laser. The compact erbium-doped fiber ring laser is constructed by using an optical integrated component and mode-locked by the nonlinear polarization rotation technique. The laser produces NLPs with a 3-dB spectral bandwidth of 60.2 nm, repetition rate of 9.36 MHz, and pulse energy of 2.8 nJ. Numerical simulations reproduce the generation of NLPs in the experiment. The NLPs are then launched into a 110-m-long HNLF and a supercontinuum with a 20-dB spectral width over 500 nm is obtained. Such a simple and inexpensive supercontinuum-generation system is a potential alternative for various practical applications.

-Switched Erbium-Doped Fiber Laser Based on Few-Layer MoS 2 Saturable Absorber

Abstract. We numerically investigate the output characteristics of dissipative solitons (DSs) in a thulium-doped fiber ring laser mode-locked by a semiconductor saturable absorber mirror (SESAM). It is shown that DSs could be formed with the SESAM acting as a mode-locker and a filtering-equivalent component. The pump power, together with the net-cavity dispersion, determines the properties of the generated DSs. The numerical results qualitatively match with previously reported experimental observations. The pulse compression of the generated DSs is numerically demonstrated by using a segment of single-mode fiber with anomalous dispersion as an external pulse compressor. The corresponding compressed pulses have a minimum duration of 450 fs.

Compact noise-like pulse fiber laser and its application for supercontinuum generation in highly nonlinear fiber

We report an experimental observation of dark pulse generation in a dispersion-managed erbium-doped fiber laser with net anomalous cavity group-velocity dispersion. It is found that apart from the bright soliton pulses, dark pulses with spectral sidebands could be obtained in the laser under appropriate operating conditions. The generation of dark pulses may be attributed to soliton shaping in the cavity.

Characteristics of dissipative solitons in an all-fiber thulium-doped fiber ring laser

We numerically demonstrate a wavelength-tunable graphene-based mode-locked fiber laser with net anomalous cavity group-velocity dispersion. It is shown that by utilizing fiber birefringence, the central wavelength of mode-locked pulses could be continuously tuned over the range from 1553 to 1566 nm. The numerical results are in agreement with the experimental observations in the literature. The mechanism of wavelength tuning may be attributed to an artificial fiber birefringence-induced filter in the cavity.

Dark pulse generation in a dispersion-managed fiber laser

We demonstrate a passively Q-switched erbium-doped fiber laser (EDFL) based on graphene as a saturable absorber (SA). Two fiber Bragg gratings (FBGs) are used as the end mirrors in an all-fiber linear cavity. The Q-switched EDFL has a pump threshold of 68.2 mW. The minimum pulse duration is 0.85 μs and the highest pulse energy is 40.9 nJ. The pulse repetition rate of the fiber laser can be widely changed from 51.1 to 118.1 kHz by increasing the pump power from 68.2 to 400 mW.

Numerical investigation of wavelength tuning in a graphene-based mode-locked fiber laser

We present a passively mode-locked erbium-doped fiber ring laser with near-zero net cavity dispersion using the nonlinear polarization rotation technique. The compact all-fiber laser is constructed by utilizing an optical integrated component. Through optimizing the cavity dispersion and nonlinearity, high-peak-power near-transform-limited pulses with a spectral width beyond the gain bandwidth limitation can be directly obtained from the laser. Resultant output pulses have a pulse duration of 62 fs, a 3-dB spectral width of 66.3 nm, and a maximum peak power of 7.9 kW. Numerical simulations reproduce the generation of sub-100-fs pulses in the laser. The pulse-shaping mechanism can be attributed to simultaneous dispersion and nonlinearity management in the cavity, which is distinct from that in the stretched-pulse lasers.

Passively Q-switched linear-cavity erbium-doped fiber laser based on graphene saturable absorber

We numerically investigate the characteristics of vector dissipative solitons (VDSs) in a graphene mode-locked fiber ring laser. The results show that the polarization rotation locked VDSs can be formed in the fiber laser.

Direct generation of 62-fs pulses in an erbium-doped fiber laser

We demonstrate a graphene-based passively Q-switched erbium-doped fiber laser. The laser produces stable pulses with a typical pulse width of ~ 9.0 μs at a pulse repetition rate ranging from 8.3 to 12.5 kHz.