High power narrow linewidth LP₁₁ mode fiber laser using mode-selective FBGs

Abstract

We demonstrated a high power Yb-doped fiber laser capable of delivering LP11 mode laser output. The oscillation of LP11 mode was realized by incorporating a pair of few-mode fiber Bragg gratings (FBGs), whose LP11 mode reflection peaks are matched with each other. The temperature-sensitivity of the FBGs was used to optimize the matching degree of the LP11 mode reflection peaks. Based on this configuration, over 50 W of LP11 mode output power with a linewidth of around 70 pm was obtained, which, to the best of our knowledge, is the highest power obtained in LP11 mode all-fiber lasers. Moreover, this laser possesses a certain stability; the standard deviation of whose output power is ~0.07% over a period of 300 s stability test. This work could provide a stable and high power LP11 transverse mode laser source for a wide range of applications.

Hundred-watt level high-order mode all-fiberized random distributed feedback Raman fiber laser with high mode purity

“…Moreover, further generation of cylindrical vector beams and vortex beams based on HOMs has also been verified [3][4][5][6][7][8][9] , which finds a tremendous range of applications, including plasmon excitation [10] , optical tweezers [11] , and electron acceleration [12] . So far, several routines to achieve HOMs have been confirmed, such as specially designed fibers [13,14] , lateral offset splicing [15] , long-period fiber gratings (LPFGs) [16][17][18] , few-mode fiber Bragg gratings (FMFBGs) [19][20][21][22] , mode-selective couplers (MSCs) [4,[23][24][25][26][27] , spatial light modulators [28][29][30][31][32] , active polarization control [33,34] , and acoustically induced fiber gratings (AIFGs) [35][36][37][38] .…”

Selective transverse mode emission from all polarization-maintaining fiber lasers

“…Proper mode filter methods, for instance utilizing fiber gratings can further increase the purity of the higher order mode from a fiber laser. Meanwhile, fiber lasers that directly oscillating at higher order LP11 mode have also been reported to increase the lasing efficiency [15]. Most of them used few-mode fiber Bragg gratings [16,17] or wavelength-divisionmultiplexing MSC [18] as mode filters.…”

All-Fiber Laser With Agile Mode-Switching Capability Through Intra-Cavity Conversion

“…Fiber lasers with pure high-order-mode (HOM) output have been intensively studied in recent years owing to their unique polarization, amplitude and phase characteristics. Generally, there are several commonly used approaches to realize HOM operation, including adopting spatial light modulators [1], [2], employing long period gratings [3], [4], introducing adaptive control [5]- [7], using few-mode fiber Bragg gratings (FBGs) [8]- [10] and taking advantage of mode selective couplers [11], [12]. Currently, exploration on HOM fiber lasers has focused on power scaling [13], nonlinear conversion [4], [14], vector beam generation [15], etc.…”