Vortex arrays directly generated from an efficient diode-pumped microchip laser

Abstract

Optical vortex arrays with multiple singularities arranged in distinct lattice structures provide more flexibility in trapping or manipulating microparticles, large-capacity optical communications and high-security information processing, and optical modulation. An efficient high-power compact laser with singularity-tunable vortex-array distribution is crucial for practical applications. Here, we directly generate various vortex arrays with tunable singularities from 1 to 10 in a microchip laser pumped with a tilted annular beam. Formation of vortex arrays in the microchip laser is achieved by manipulating the gain distribution in an Yb:YAG crystal by controlling the tilt angles and pump power. Efficient high-power laser operation with output power of 2.01 W and optical efficiency of 24.5% is obtained for a vortex array with 10 singularities. The pump-power-dependent saturated population inversion distribution plays a key role in generating vortex arrays formed with multi-transverse modes oscillating simultaneously in transverse-mode locking. The good agreement between theoretically simulated transverse patterns, phases and interference patterns for the vortex arrays and experimentally obtained results provides a solid foundation for developing efficient compact microchip lasers for generating vortex arrays by manipulating gain distribution in a thin medium pumped with a tilted annular beam.

Pulsed Optical Vortex Array Generation in a Self-Q-Switched Tm:YALO3 Laser

“…The Hermite–Gaussian (HG), Laguerre–Gaussian (LG), and Ince–Gaussian (IG) modes represent eigenmodes in laser resonators. OVAs have typically been described as the result of the coherence superposition of these eigenmodes [ 20 ]. By harnessing transverse mode locking, specialized laser resonators enable the creation of OVAs.…”

“…Optical vortex lattices in a thin-slice Yb:CALGO laser have been achieved by precisely controlling the pump aperture and off-axis displacement [ 34 ]. A range of OVAs with adjustable singularities, ranging from 1 to 10, has been generated within a microchip laser system by employing a tilted annular beam as the pump source [ 20 ]. We have directly generated OVAs in all-solid-state lasers operating at wavelengths of 1 μm and 3 μm by using the off-axis pumping method and introducing defect spots within the cavity [ 35 , 36 ].…”

Broadband 2D n × n Vortex Arrays Generated from an Efficient Petal‐Like Raman Laser with an Astigmatic Mode Convertor

“…[30] Optical vortex arrays were directly generated in a Yb 3+ :Y 3 AL 5 O 12 (Yb:YAG) microchip laser under tilted annular beam pumping. [31] 1D optical vortex arrays with tunable singularities and high peak power have been generated in a passively Q-switched microchip laser pumped with a decentered annular beam. [32] The astigmatic mode converter (AMC) has been widely used to convert Laguerre-Gaussian in form of zero radial index and l azimuthal index (LG 0,l ) petal-like laser into crisscross vortex-arrays superpositioned with two orthogonal Hermite-Gaussian (HG) modes in the form of HG l,0 þe Àiπ/2 HG 0, DOI: 10.1002/adpr.202200293 Broadband vortex arrays distributed in 2D n  n vortices are extremely needed for multiple microparticle manipulation, high-capacity optical communication, and quantum information.…”