Abstract: Erbium-ytterbium heavy co-doped phosphate glasses with different concentrations have been fabricated. Absorption spectra, excitation spectra, emission spectra have been measured and optical parameters are calculated with J-O theory and Dexster theory. With the glasses of a few millimeters with good optical performance, the laser emission was demonstrated. More than 80 mW laser output was obtained with a 1mm Er-Yb-codoped phosphate glass. The glasses with good absorption and fluorescence performance were chosen to draw fibers. Laser emissions of the fibers were demonstrated. A propagation equation and rate equation model for the lasers, which considers the cumulative transfer and double-energy transfer processes, is established. The physical transition mechanisms are analyzed. The simulation for the lasing operation of a short Er³⁺-Yb³⁺-codoped phosphate fiber laser is investigated. A 10.4 cm compact fiber laser with an output power of 170.4 mW, a bandwidth of 0.053 nm and a slope efficiency of 35.3% is demonstrated in experiments. The experimental results show that the theoretical model we used is more accurate than former models. The dependence of output power on output coupler reflectivity, active fiber length and Er³⁺-Yb³⁺ concentrations are also investigated numerically. We also demonstrated the super fluorescence source with 8-15cm fibers.

About Speaker:Feng Song, professor in Nankai University. His research interests include solid state lasers and their applications, fabrication and luminescence of rare earth doped materials, compact fiber lasers and amplifiers, broadband ASE light sources, emission enhancement by surface plasmon polariton, nanostructure and the influence on the radiative and nonradiative decay. He received his PhD degree from Tianjin University(excellent level) and master degree from Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences(excellent level), and bachelor degree from Heifei University of Technology(excellent level).He used to work as a postdoctor in Optical Science Center of University of Arizona, and visiting professor in Department of Physics, Moscow University, Russia, and in Department of Electronics Engineering, City University of Hong Kong. He also acted as the program director in Section of Optics & Opto-electronics, National Science Foundation of China (NSFC). Dr. Song has about 20 years of academic and industrial experience in photonic materials and devices. He is the holder of several patents and has published over 100 papers, among which about 80 in internationally recognized journals, and has given invited presentations at national and international conferences. He has been served as program member for national and international academic conferences including SPIE Photonics West (Section of optical components and materials). He is serving as vice editor-in-chief for Journal of University Physics (in Chinese), a topical editor of Applied Optics., executive member in sub-committee of optics-mechanics-electronics integration of Chinese Instrument Committee, the vice executive chair for Tianjin Society of Laser Technology, the general secretary of Tianjin Society of Physics. He is also approved to be a member of Teaching Guidance Committee on University Physics by National Ministry of Education. He also served as an independent juror for International Young Physicst Tournament from 2008.