Vortex random fiber laser with controllable orbital angular momentum mode

Abstract

In this paper, we propose and experimentally demonstrate a vortex random fiber laser (RFL) with a controllable orbital angular momentum (OAM) mode. The topological charge of the vortex RFL can range from − 50 t o 50 with nearly watt-level output power. A triangular toroidal interferometer is constructed to verify the spiral phase structure of the generated vortex random laser with a special coherence property. Vortex RFLs with fractional topological charge are also performed in this work. As the first demonstration of a vortex RFL with a controllable OAM mode (to the best of our knowledge), this work may not only offer a valuable reference on temporal modulation of a vortex beam and optical field control of an RFL but also provide a potential vortex laser source for applications in imaging, sensing, and communication.

Digital generation of super-Gaussian perfect vortex beams via wavefront shaping with globally adaptive feedback

“…The salient properties of RFLs are highlighted by the non-resonant lasing structure, the strongly suppressed temporal intensity fluctuation [ 33 ] and the low spatial coherence [ 34 ] , which are promising for the laser seed of ICF. Although random vortex beams have been reported based on the spatial light modulator [ 35 ] and long period fiber grating [ 36 ] , the performances in terms of the achievable topological charge and the beam profile quality still have huge room for improvement. Here, a half-open cavity-based random lasing light source is employed.…”

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] .…”

High-charge perfect vortex beam generation

“…On the other hand, the quality of the incident lasing also plays a pivotal role in passive modulated vortex beam generation. As an advanced fiber laser, Random fiber lasers (RFLs) [3] have been introduced into vortex beam generation by employing mode selective coupler [4], SLM [5], and all-fiber based LPFG [6]. Interesting characteristics have been verified benefiting from the unique features of RFL, such as low spatial coherence, high output power, and flexibly tunable lasing wavelength.…”