Ultra-short pulse laser has the advantages of high peak power, short duration of action, wide spectrum and so on. It has a wide range of applications in basic science, medical, aerospace, quantum communication and military fields. Especially in recent years, the rapid development of femtosecond fiber burning laser because of simple structure, low cost, high stability and easy to carry and so on, showing more and more widely used prospects. At present, fiber-mode-locked lasers, including other types of solid-state lasers, have to achieve stable mode-locked operation and more time to rely on saturable absorbers, but not only because of the laser damage and loss caused by saturable absorbers. Constraints can produce the laser pulse width and power, will also affect the reliability of long-term operation.
Therefore, the research and development of new saturable absorber with high damage threshold and low loss has attracted much attention of laser experts and materials experts. In the past more than 10 years, with the development of condensed matter physics and material preparation technology, carbon nanotubes, graphene, topological insulator as saturable absorption materials have been successful in the application of mode-locked 100mw laser pointer, especially the newly developed two-dimensional nano materials with narrow band gap, ultrafast electron relaxation time and high the damage threshold, exhibits excellent saturable absorption, utilization of the mode-locked laser materials has become one of the hot research content of people's attention.
Chinese Research Institute of physics, Beijing Key Laboratory of optical physics, Condensed State Physics National Laboratory L07 group has been committed to the development of ultrafast laser, the miniaturization of femtosecond laser in recent years, has achieved the multi crystal and fiber laser passively mode-locked saturable absorption. By using a pulsed laser deposition method of antimony telluride topological insulator formed on the surface of uniform growth of tapered fiber saturable absorber, for the first time the hybrid fiber blue laser pointer mode-locked, the output pulse with 70 FS results. By using two tungsten sulfide with ultrashort electron relaxation time as the saturable absorber, with decreasing the core diameter of tapered fibers, obtained 67 FS mode-locked pulse output, verified the advantages of the hybrid mode-locked fiber laser with shorter pulse width, low timing jitter.
In addition to dark soliton generation technology, the relationship through the theoretical calculation of fiber laser Ginzburg- Landau equation in gain and loss and dispersion and nonlinear parameters, the theoretical analysis of the dynamic mechanism of the formation of the dark soliton, obtained SNR results up to 94 dB, the experiment is implemented on a wide spectrum of the dark soliton pulse. The research group in collaboration with the Beijing University of Posts and Telecommunications recently, two tungsten sulfide as a saturable absorber material for optical fiber mode-locked laser, and further realize the pulse width of 246 FS mode-locked 5mw laser pointer output, which is so far known to transition metal sulfides of all fiber mode-locked laser generated by the short pulse report.