Pulsed fiber lasers, with high peak power and narrow pulse widths, have been proven to be an important tool for a variety of fields of application. In this work, frontier and hot topics in pulsed fiber lasers were analyzed with 11,064 articles. Benefitting from the scientometric analysis capabilities of CiteSpace, the analysis found that passively mode-locked fiber lasers with saturable absorbers (SAs) based on two-dimensional (2D) materials have become a hot research topic in the field of pulsed fiber lasers due to the advantages of self-starting operation, high stability, and good compatibility. The excellent nonlinear optical properties exhibited by 2D materials at nanometer-scale thicknesses have become a particularly popular research topic; the research has paved the way for exploring its wider applications. We summarize the performance of several typical 2D materials in ultrafast fiber lasers, such as graphene, topological insulators (TIs), transition metal dichalcogenides (TMDs), and black phosphorus (BP). Meanwhile, we review and analyze the direction of the development of 2D SAs for ultrafast fiber lasers.
Although the physicochemical properties of gallium selenide (GaSe) have been widely investigated, the property and application exploration of GaSe‐coupled fiber devices are still in its infancy. There are obvious challenges, namely, selecting from multiple GaSe phases and effectively coupling to the unique fiber structure. Herein, lab‐on‐fiber (LOF) based on optimized GaSe is proposed to be used for robust femtosecond pulse generation and fiber‐compatible photodetection. First, based on density functional theory (DFT) calculations, ε‐GaSe is selected as a preferable model material for its suitable band structures, low work function, and high damage threshold. Benefiting from the fiber‐compatible ε‐GaSe combined with micro–nano processing, stable femtosecond soliton pulse (≈303 fs, 16.67 MHz, 51.64 dB) output and multiwavelength (520, 808, and 1550 nm) detection are realized in LOF. These results pave the way for optics research of polyphase semiconductors and design of integrated all‐fiber devices.
Gallium sulfide (GaS), with a hexagonal structure, has received extensive attention due to its graphene-like structure and derived optical properties. Here, high-quality GaS was obtained via chemical vapor synthesis and then prepared as a saturable absorber by the stamp-assisted localization-transfer technique onto fiber end face. The stability of the material and the laser damage threshold are maintained due to the optimized thickness and the cavity integration form. The potential of the GaS for nonlinear optics is explored by constructing a GaS-based Erbium-doped mode-locked fiber laser. Stable femtosecond (~448 fs) mode-locking operation of the single pulse train is achieved, and the robust mode-locked operation (>30 days) was recorded. Experimental results show the potential of GaS for multi-functional ultrafast high-power lasers and promote continuous research on graphene-like materials in nonlinear optics and photonics.
The magnetic nanomaterial Mn3Si2Te6 is a promising option for spin-dependent electronic and magneto-optoelectronic devices. However, its application in nonlinear optics remains fanciful. Here, we demonstrate a pulsed Er-doped fiber laser (EDFL) based on a novel quasi-2D Mn3Si2Te6 saturable absorber (SA) with low pump power at 1.5 μm. The high-quality Mn3Si2Te6 crystals were synthesized by the self-flux method, and the ultrathin Mn3Si2Te6 nanoflakes were prepared by a simple mechanical exfoliation procedure. To the best of our knowledge, this is the first time laser pulses have been generated using quasi-2D Mn3Si2Te6. A stable pulsed laser at 1562 nm with a low threshold pump power of 60 mW was produced by integrating the Mn3Si2Te6 SA into an EDFL cavity. The maximum power of the output pulse is 783 μW. The repetition rate can vary from 24.16 to 44.44 kHz, with corresponding pulse durations of 5.64 to 3.41 µs. Our results indicate that the quasi-2D Mn3Si2Te6 is a promising material for application in ultrafast photonics.
The realization of controlled modulation of ultrashort pulses in the all-solid-state visible ultrafast lasers is a challenge, limited by the development of advanced optical modulation devices. Here, we reported a Ta2PdSe6 photonic device-based controlled visible ultrafast laser that exploits the polarization-dependent optical response of the Ta2PdSe6 photonic device to modulate the pulse width. Ultrashort pulse widths of 33.3 ps and 36.6 ps can be achieved under the horizontal and vertical polarization emission, respectively. This study presents polarization-dependent photonic devices for solid-state lasers, which might lead to the creation of controlled modulation in visible ultrafast lasers.