Abstract
While micro-ring lasers is a step forward for the miniaturization of fiber lasers, up-conversion quenching due to ion energy transfer may limit the device size and deteriorate system performance. The effect of Er3+ concentration quenching on the characteristics of silica-based Er-doped fiber (EDF) micro-ring laser was investigated. In particular, the dependence on Er3+ concentration and laser size of threshold pump power and quantum efficiency is discussed. To achieve high laser efficiency, it was found that ring diameter has to be similar to 150 mu m with similar to 5 wt.% erbium concentration. The threshold value is increased by a factor of 340, for such laser characteristics compared with threshold power when up-conversion is not considered. Moreover, we show that detrimental effect due to up-conversion quenching can be reduced by careful micro-ring laser design. (c) 2008 Elsevier B.V. All rights reserved.