Broadband One‐Dimensional Vortex‐Arrays With Singularities up to 5 Generated in a Raman Laser

ABSTRACT One‐dimensional (1D) vortex arrays (VAs) carrying multiple phase singularities arranged linearly have significant promise for applications in flexible multiparticle manipulation, assembly micro‐processing, and optical communications. The broadening of their lasing range and wavelengths significantly enhances their versatility for practical applications. However, 1D‐VAs generated in solid‐state lasers with external cavity methods suffer from instability and inefficiency. Here, we present a simple efficient approach for achieving stable broadband 1D‐VAs with phase singularities up to five in a compact Yb:YAG/KTP Raman laser pumped with a tilted beam. The optical vortices of 1D‐VAs are controlled by adjusting the incident pump power (P in ). All 1D‐VA Raman lasers oscillate within a pump power range of over 1 W. For the 1D‐VA with five singularities, the maximum output power reaches 230 mW at P in = 6.4 W, and the optical conversion efficiency is 3.6%. The 1D‐VA with five singularities oscillates in 59 longitudinal modes and covers a laser spectral range of 14.6 nm. The 1D‐VA with five singularities operating from 1086.1 to 1100.7 nm generated in Yb:YAG/KTP Raman laser opens a new window for developing compact Raman lasers to generate 1D‐VAs with multiple singularities for assembly manipulation of microparticles and micro‐processing.