Pump induced instability and suppression of pulsed fiber laser amplifier system

• Main Authors: Huai-Shuan Chiu, 邱懷萱
• Other Authors: Tsin-Dong Lee
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/08108461576982970693

碩士 === 雲林科技大學 === 光學電子工程研究所 === 97 === 　　In recent years, Self pulse phenomenon has been widely studied in rare earth doped CW fiber laser system. It can be affected by pump power, length of gain fiber, cavity, and temperature. However, it remained an important subject for the suppression of self pulse in pulsed fiber laser amplifier system. Especially due to the directionless property which could generate a giant pulse which along reverse laser signal direction. Eventually, it might damage the devices such as laser diode, isolator, and even combiner. 　　In this paper, a fiber laser amplifier with different pump configuration and no laser signal input has been used to evaluate ASE instability threshold. Experiment presents that the output ASE power instability can be observed in a fiber laser amplifier system with core diameter 6 um and length of 4 meter Ytterbium doped fiber while a 2W pump power is launched in forward pumping. However, bi-directional pumping configuration can increase instability threshold to 2.3W. In the two kind configurations of the pump, when the length of the gain fiber is shorter, producing the threshold of the self pulse will be increased. The result of our experiment can be useful to evaluate fiber base amplifier performance and limitation.