Optical Radiative Properties Of Rare Earth-doped Polymer Optical Fiber

Polymer optical fiber (POF) is promising for appliances in local area networks, optical sensors and functional optical fiber devices, and so on. The optical properties, radiative properties of rare earth-doped polymer optical fiber materials and optical amplification characteristics of rare earth-doped polymer optical fiber have been studied in this thesis.The optical properties and radiative properties of Nd~3+-doped polymer optical fiber developed by us were analysed thoroughly. Based on Judd-Ofelt theory, the Judd-Ofelt intensity parameters were calculated using the absorption spectrum of Nd3+-doped polymethyl methacrylate(PMMA). The Judd-Ofelt intensity parameters were used to calculate the radiative transition probabilities of the 4F3/2→4IJ transition, the fluorescence branching ratios of the 4F3/2→4IJ transition, the radiative lifetime of 4F3/2 level and the stimulated emission cross-sections of the 4F3/2→4I11/2 transition.The optical properties and radiative properties of Eu(DBM)3-doped PMMA polymer optical fiber have been studied. Using Judd-Ofelt theory, the radiative transition probabilities of the 5Do→7FJ' transition, the fluorescence branching ratios of the 5Do→7FJ transition, the radiative lifetime of 5Do level and the stimulated emission cross-sections of the 5Do→7FJ transition were calculated by emission spectrum of Eu3+ ions. The fluorescence lifetime of 5Do level was measured.Using the rate equation for four-level-system, laser theory and the parameters calculated above, the Nd(DBM)3-doped polymer optical fiber amplifier was simulated, including the relations of signal gain versus opticalfiber length, pump power, fiber core radius, Nd3+ ions metastable state fluorescence lifetime and pump absorbance section of Nd3+ ions.