Highly efficient Yb-free Er-La-Al doped ultra-low Na large mode area single-trench fiber laser

Abstract

Abstract:We demonstrate a 60µm core diameter Yb free Er-La-Al doped single-trench fiber having a 0.038 ultra-low-NA, fabricated using conventional MCVD process in conjunction with solution doping technique. Numerical simulations predict an effective single mode operation with effective area varying from 1,820µm 2 to 1,960µm 2 (taking bend-induced modal distortion into account) for different thicknesses of trenches and resonant rings at a constant bend radius of 25cm. Moreover, all solid structure favors easy cleaving and splicing. Experimental measurements demonstrate a robust effective single mode operation. Furthermore, with a 4%-4% laser cavity, this fiber shows a record efficiency of 46% with respect to the absorbed pump power. 24575-24584 (2012). 9. C. Jauregui, J. Limpert, and A. Tunnermann, "High-power fiber lasers," Nat. Photonics 7(11), 861-867 (2013) (Invited). 10. D. Jain, C. Baskiotis, and J. K. Sahu, "Mode area scaling with Multi-trench rod-type fibers," Opt. Express 21(2), 1448-1455 (2013). 11. V. Khitrov, V. V. Shkunov, D. A. Rockwell, Y. A. Zakharenkov, and F. Strohkendl, "Er-doped high-aspect-ratio core rectangular fiber producing 5 mJ, 13 ns pulses at 1572 nm," Opt. Lett. 37(19), 3963-3965 (2012). 12. D. Jain, Y. Jung, P. Barua, S. Alam, and J. K. Sahu, "Demonstration of ultra-low NA rare-earth doped step index fiber for applications in high power fiber lasers," Opt. Express 23(6), 7407-7415 (2015). 13. D. Jain, Y. Jung, M. Nunez-Velazquez, and J. K. Sahu, "Extending single mode performance of all-solid largemode-area single trench fiber," Opt. Express 22(25),

Segmented Cladding Fiber With a High-Index Ring in Core for Wideband Single-Mode Operation in Any Bending Orientation

“…In order to overcome the difficulty caused by the fiber nonlinear effect, several special large mode area (LMA) fibers operating with effective single-mode (SM) are proposed [14][15]. These novel designs include photonic crystal fibers (PCFs) [16], leakage channel fibers (LCFs) [17][18], brag fibers (BFs) [19], all-solid photonic bandgap fibers (AS-PBFs) [20], chirally-coupled-core fibers (CCCFs) [21], Gainguided, index anti-guided fibers (GG+IAGFs) [22], segmented cladding fibers (SCFs) [23], single-trench fibers (STFs) [24], and multi-trench fibers (MTFs) [25][26].…”