64results about How to "Improve doping uniformity" patented technology

The invention relates to a rare-earth uniformly-doped fiber perform core rod and a preparation method thereof. The core rod adopts silicon dioxide used as a matrix and is at least doped with a rare earth ion and a co-doping ion, wherein the doping concentration of the rare earth element is calculated in the oxide form; the concentration of the doped rare earth oxide is 0.05-0.5mol%; the co-doping ion is at least one of Al and P elements; the co-doping agent concentration is calculated in the oxide form; and the concentration of the co-doping agent oxide is 0.4-10mol%. The core rod is prepared by adopting a powder forming-sintering method. The core rod disclosed by the invention has the advantages that the fiber core has high doping uniformity in the axial direction and the radial direction; the refractive index profile of the fiber core has high flatness; the numerical aperture (NA) of the fiber core is accurate and adjustable; and the optical fiber has high slope efficiency. Based on the rare earth doped core rod, various rare-earth doped optical fibers with different structures can be manufactured by using a core rod through the external cladding technology, i.e., the manufacturing requirements of rare earth doped optical fibers with different structures such as single cladding single mode, double cladding single mode, polarization-maintaining double cladding, large-mode field area air hole double cladding and the like are satisfied.

The embodiment of the present invention discloses a method for preparing a carbon-silicon composite material. By uniformly dispersing hydrocarbyl borane, nano-scale silicon powder and graphene, performing a hydrothermal reaction at 100-200°C, drying the product, and using NH3 and inert The mixed gas of the gas carbonizes the hydrothermal reaction product, and then passes through the conductive polymer monomer supported by the inert gas to react. The composite material has a core-shell structure, the inner core is an aggregation molding of nano-scale silicon powder, the inner core is doped with B elements, and the outer shell is doped with N and B elements. The core nano-scale silicon powder of the present invention is doped with boron by hydrothermal method to form a porous structure, which can reduce the expansion of silicon in the process of charging and discharging. Specific capacity and electronic conductivity, the shell layer is doped with a certain amount of boron and nitrogen elements, which is beneficial to the improvement of the specific capacity and the reduction of the impedance of the composite material.