Generation of 6.8 W of CW output power at 1550 nm using small mode field diameter Er:Yb co-doped double clad fiber in laser oscillator configuration

• Published in: Laser physics 2017-06, Vol.27 (6), p.65113
• Main Authors: Gurram, Srikanth, Kuruvilla, A, Singh, Rajpal, Bindra, K S
• Format: Article
• Language: English
• Subjects: EYDF laser; FBG; fiber laser; laser
• ISSN: 1054-660X; 1555-6611
• DOI: 10.1088/1555-6611/aa6da1

We report studies on erbium:ytterbium doped fiber laser, that uses a commercially available off-the-shelf Er:Yb co-doped single mode fiber with small mode field diameter of 7 µm, which is compatible with single mode fibers used in most of the communication systems. In a FBG based laser oscillator configuration pumped at 976 nm, the single transverse mode fiber laser emitted more than 6.87 Watts of output power at 1550 nm with a conversion efficiency of ~32% over a narrow line width. The pump radiation is coupled into active fiber using free-space optics. To the best of our knowledge, this is the highest power reported in the 1.55 µm region by using commercially available off-the-shelf active fiber of small mode field diameter (~7 µm) in a simple laser oscillator configuration with 9×× nm pumping. We also observed the effect of weak secondary grating structure in FBGs on the spectral characteristics of EYDFLs and explained its significance for co-doped fiber lasers such as erbium-ytterbium fiber lasers.