Characterization of multiplets in a Nd³⁺‐doped polymer optical fiber with low ion concentration

Abstract

Abstract A new model is established to infer a ratio of multipleted ions to the total ions (ρ) based on rate equations of ionic transferring between excited and unexcited states, which is designed for rare earth containing polymer optical fiber (POF) with low ion concentration ranging from 30 to 200 ppm. A step‐index (SI) Nd 3+ ‐doped POF was made from a preform which was prepared by using bulk polymerization of methyl methacrylate (MMA) with a certain amount of neodymium octanoate (NOA) as a dopant, 2,2‐azoisobutyronitrile (AIBN) as an initiator, and n ‐butyl mercaptan as a chain‐transfer agent. The measurement of transmission at 810 nm of the Nd 3+ ‐doped POF was made by fitting experimental data and by using the theoretical model, the values of ρ at different Nd 3+ concentration could be obtained. The result showed that the ratio is 0.03, 0.08, and 0.3 for Nd 3+ ‐doped POF at Nd 3+ concentrations of 70, 100, and 200 ppm, respectively. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2033–2040, 2002