Fabrication Of Bismuth Doped Silica Based Fiber And Research On The Spectral Properties

Now the bismuth doped materials have drawn muth attention for its huge proficiency.Dvoyrin reported the first bismuth doped fibers in2005and relized laser in the region of1150-1500nm. Howerer, there are also two factors restrict its further application:(1) themechanism of the NIR emission is unclear yet and the NIR emission intensity of bismuth istoo weak for practical application.(2) It is very hard to prepare the bismuth doped fiber,because the Bi is very easy to volatilize when bismuth doped fiber was prepared in hightemperature. Therefore, there is no report that single bismuth doped fiber can emitfluorescence in all optical fiber communication wavelenth.This paper is to solve the above problem. The main topics of this thesis are the methodsto enhance the NIR emission and the nature of NIR luminescence. Bismuth doped fiber wereprepared to study the spectral properties. The main content of the thesis includes:(1) Aluminum and bismuth co-doped silicate glasses were prepared with reducing agent(Al powder). Effects of Al on the absorption spectrum, NIR emission and visible regionemission of bismuth doped glasses was discussed, and compared to the influence of alkalimetal on NIR emission of bismuth doped glasses. It is indicated that Bi-related NIR emissioncenter may be attributed to the electronic transition of Bi+.(2) It is discuss the effect of the type of quartz glass tube, dopant ions and preparationprocess on formation of Bi-NIR active center when perform was prepared. The Bi ions candope easily when perform was prepared using the lower shrinkage rod temperature tube.Oxidizing atmosphere should be avoided in the preparation of bismuth doped optical fiber,like Yb3+ion, it is appropriate to increase the reducing atmosphere. Solution doping mathedis batter than gas phase doping mathed when the bismuth doped perform was prepared.(3) It is found the luminescence of perform slice in the wavelength of1000-1600nm.The emission intensity increases with heat treatment of perform slice. An ultra-broad NIRemission in the wavelength of1000-1700nm is observed in the bismuth doped fiber. Theresults indicate that the bismuth doped fiber is promising gain medium used as fiber lasersand amplifiers.