| To replace the electron by photon or opto-electronic as information carriers is the future of information technology development. The three main objectives to be achieved, are the large capacity data transmission, blazing fast real-time information processing and ultra high density information store in the age of information。From the end of the 1980s, Erbium-doped fiber amplifiers (Erbium Doped Fiber Amplifiers, EDFA) implementation been extensively utilized in the long-distance optical communication, enabling WDM (Wavelength Division Multiplexing, WDM) technology to become reality, which significantly boost the performance of the information age of the historical process. However, the gain bandwidth of the Rear-earth Doped Fiber Amplifiers (RDFA)cannot surpass 100 nm due to the nature of the inner shell transition of rare-earth ions, which limits the transmission capacity of optical fiber communications. With the boost of optical communication, the the gain bandwidth of RDFA cannot satisfy the need of application.In 2001, Fujimoto et al discovered broadband infrared luminescence from bismuth-doped glasses, since then bismuth-doped glasses have attracted much attention. Bismuth-doped glasses exist the characteristics of wider bandwidth and longer lifetime than RDFA, therefore, once bismuth-doped glasses are used as matrix materials for optical amplifier, the low loss communication window could be covered by a single fiber. However, at present, the mechanism of infrared luminescence is still unclear, and bismuth-doped glasses have some disadvantages, therefore, the effect of glass matrix on broadband luminescence of bismuth-doped glass should be investigated, as well as the mechanism of infrared luminescence. It is expected that the research results above will be useful to choose better glass matrix for broadband luminescence, overcome disadvantages of bismuth-doped glasses, so as to achieve more excellent broadband luminescence.In this thesis, bismuth-doped aluminosilicate glasses were selected as research subjects, and the effect of glass matrix structure on bismuth ions broadband photoluminescence were investigated. In the silicate glass system, influence of different compositions and the glass micro-structural on the broadband luminescence of bismuth ions have been realized. Also, the mechanism for the infrared luminescence of bismuth ions was discussed. The research results will be a great help for the further study in the field.The introduction describes the development of fiber optical communication, fiber amplifier types and the RDFA in use, and describe the basic work principles; and then describes as fiber amplified material of Bi-doped glasses, and indicating its limitations; at last presented on Bi-doped glass UWB luminescence of purpose and meaning.In chapter 2 is the experimental section.In Chapter 3, the near infrared fluorescence with the full width at half maximum(FWHM) larger than 200 nm was observed in bismuth doped SiO2-Al2O3-CaO glasses. The influence of optical basicity on broadband infrared fluorescence was investigated in bismuth doped aluminosilicate glasses. The intensity of the infrared fluorescence decreases with the increase in the optical basicity of glass hosts. On the base of the fluorescence spectra, we thought the infrared fluorescence might be attributed to low valence bismuth ions. Influence of alkaline earth oxides on super broadband near infrared luminescence properties from Bi-doped RO-Al2O3-SiO2 (R=Ca, Sr, Ba) aluminosilicate glass were investigated. The results show that under different pumping source, the near infrared (NIR) luminescence showed different behavior. Under 808 nm excitation, the infrared emission located at 1300 nm with lifetime more than 600μs was observed, whose intensity increased with increasing of ionic radius. However, under 690 nm excitation, the luminescence at 1100 nm with full width at half maximum of 400 nm decreased with the increase of ionic radius. According to the above results, it is suggested that infrared emissions may be from Bi+and Bi2+In Chapter 4,we investigated the dependence of infrared emission on the change of glass microstructure in Bi-doped aluminosilicate glasses.The change of aluminium ion content of alumiosilicate glass system effect the microstructure of silicate glass which made the the emission spectra changed correspondingly; It is indicated that the change of network structure of glass matrix affects the infrared luminescence a lot based on the above result. Compare and analyze the infrared broadband emission of bismuth ions with different aluminium content. The result shows, infrared luminescence spectra match along with the aborption spectra. Both of them were affected by the network structure of glass matrix composed with SiO2 and Al2O3. The phenomenon of aluminum deregulation has been investigated in SACB3 glass.Chapter 5 summarizes the results of this reaserch. The existed problem and further research direction were pointed out. |
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