A methode of estimating the reflectivity and refractive-index modulation of double-cladding large core fiber Bragg grating

作者：Zhou Ren Lai^*; Ju You Lun; Yang Chao; Wang Wei; Wang Yue Zhu

来源：Acta Physica Sinica, 2012, 61(24): 244205.

DOI：10.7498/aps.61.244205

• reflectivity
• refractive-index modulation
• fiber Bragg gratings
• Tm3+ doped fiber laser

A simple and practical method of estimating reflectivity and refractive-index modulation is reported when writing fiber Bragg grating (FBG) into silica fiber core based on 800 nm femtosecond laser pulses and a phase mask. By monitoring and recording the variation of the fiber laser output power, the reflectivity and refractive-index modulation are estimated theoretically and experimentally. The reflectivity of FBG is approximate 96.4%, and the refractive-index modulation is about 1.2 x 10(-3). When the FBG is used as a linear cavity mirror, 15.5 W of output power is obtained under an incident pump power of 51.6 W, corresponding to a slop efficiency of 37.9%. A beam factor of M-2 = 1.4 at an output power of 15 W is measured by using the knife-edge method.

• 出版日期2012
• 单位哈尔滨工业大学