Chinese Optics Letters, 2019, 17 (12): 120602, Published Online: Nov. 27, 2019
Ultra-broadband highly efficient mode converter at 1 μm fabricated by a line-focused CO2 laser
060.2340 Fiber optics components 060.3735 Fiber Bragg gratings 060.2330 Fiber optics communications 140.3510 Lasers, fiber
Abstract
We report here an ultra-broadband linearly polarized (LP) LP01 LP11 mode converter operating at 1 μm based on a long period fiber grating (LPFG) fabricated in a conventional two-mode fiber (TMF) by a line-focused CO2 laser. The measured 3 dB bandwidth is about 240 nm, which is the broadest bandwidth for such fiber mode converters. The maximum conversion efficiency between the LP01 and LP11 modes is >99% over the range of 1000 nm to 1085 nm, almost covering the whole emission band of Yb3+, which is useful for further power scaling of high-power fiber lasers operating at the 1 μm band.
Xin Tian, Hao Li, Le Liu, Meng Wang, Xiaoming Xi, Zefeng Wang. Ultra-broadband highly efficient mode converter at 1 μm fabricated by a line-focused CO2 laser[J]. Chinese Optics Letters, 2019, 17(12): 120602.