摘要
In this paper,a technique combining the cascaded energy-transfer pumping(CEP)method and master-oscillator power-amplifier(MOPA)configuration is proposed for power scaling of 1.6-μm-band single-frequency fiber lasers(SFFLs),where the Er^(3+)ion has a limited gain.The CEP technique is fulfilled by coupling a primary signal light at 1.6μm and a C-band auxiliary laser.The numerical model of the fiber amplifier with the CEP technique reveals that the energy transfer process involves the pump competition and the in-band particle transition between the signal and auxiliary lights.Moreover,for the signal emission,the population density in the upper level is enhanced,and the effective population inversion is achieved thanks to the CEP.A single-frequency MOPA laser at 1603 nm with an output power of 52.6 W and an improved slope efficiency of 30.4%is experimentally obtained through the CEP technique.Besides,a laser linewidth of 5.2 k Hz and a signal-to-auxiliary laser ratio of 60.7 d B are obtained at the maximum output power.The proposed technique is anticipated to be promising for increasing the slope efficiency and power scaling for fiber lasers operating at L band.
基金
National Key Research and Development Program of China(2017YFF0104602)
Major Program of the National Natural Science Foundation of China(61790582)
NSFC(11674103,51772101,61535014,61635004)
Guangdong Key Research and Development Program(2018B090904001,2018B090904003)
Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program(2017BT01X137)
Natural Science Foundation of Guangdong Province(2016A030310410,2017A030310007)
Science and Technology Project of Guangdong(2016B090925004,2017B090911005,201804020028)。
