Ultrashort pulsed fiber laser is easy to operate, compact in structure, stable in performance and low in cost. It is widely used in high speed optical communications, optical sensing, optical frequency comb, laser radar, spectrum analysis, military and other related fields. One of the hot topics in the field. At the same time, as a frontier topic in the study of nonlinear optics, ultrashort pulsed fiber laser technology has become one of the core technologies of national strategy and high-end industrial industries. In order to realize the ultra-short pulse fiber laser output, how to further recognize the nonlinear dynamics of the fiber laser and realize the non-linear control of the optical devices in the laser cavity are the key scientific issues involved in this technology.
Liu Wenjun, Lei Ming and other young teachers at Beijing University of Posts and Telecommunications have limited the pulse generation technology of dark soliton, and theoretically analyzed the dynamic behavior of dark soliton pulse generation and experimentally achieved the most broad-spectrum dark soliton pulse output. Based on the nonlinear Schr? Dinger equation and the complex Ginzburg-Landau equation, the transmission characteristics of dark soliton pulses in fiber lasers are studied by changing the nonlinear parameters of the optical fiber. The method of attenuating the interaction of dark soliton pulses is theoretically proposed. In the experiment The stable output of the dark soliton pulse in the fiber laser is achieved. After theoretical calculations, the dispersion and nonlinear parameters of the fiber laser are further optimized, and the most wide-spectrum dark soliton-pulsed fiber laser is successfully developed. The shortest pulse width is achieved by the synergetic optimization of the tapered fiber and the saturable absorbing material fs hybrid mode-locked fiber laser output. The group will also be used for all-fiber laser mode-locked, and further to achieve a pulse width 246 fs mode-locked pulse laser output. It is known that this is by far the transition metal sulfide all-fiber mode-locked laser produced by the shortest pulse width reported.
Galvanized steel sheet is carbon steel sheet coated with zinc on two sides. the process used to do this is known as the continuous hot dip process. this process results in a layer of zinc which adheres tightly to the base steel and has a spangled, or snowflake-type, appearance. The layer of zinc acts as a sacrificial coating.
Galvanised steel is mild steel with a coating of zinc The zinc protects the steel by providing cathodic protection to the exposed steel, so should the surface be damaged the zinc will corrode in preference to the steel Galvanised steel is one of the most widely used products, used extensively in the building sector, automotive, agricultural and other areas where the steel needs to be protected from corrosion.
Hot-Dip Galvanizing or HDG is a process in which zinc bonds to steel at the molecular level to produce a four-layer corrosion-resistant finish. The first three layers are zinc-iron alloy layers that are actually harder than the base steel. The fourth or top layer is pure zinc.
Galvanized Steel Sheet, Hot Dipped Galvanized, Galvanized Sheet Coil, Gi Sheet
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