2016/06/29 by N. Apurv Chaitanya, Chaitanya, N. Apurv, M. V. Jabir +5
Medicine · Physics and Astronomy · #Corneal surgery and disorders #FOS: Physical sciences #Ocular Surface and Contact Lens #Optics (physics.optics) #Orbital Angular Momentum in Optics
paper · pdf · doi:10.48550/arxiv.1606.09005
openalex publication_date 2016/06/29 · openalex created_date 2016/07/22 · openalex updated_date 2026/07/28
Hollow Gaussian beams (HGB) are a special class of doughnut shaped beams that do not carry orbital angular momentum (OAM). Such beams have a wide range of applications in many fields including atomic optics, bio-photonics, atmospheric science, and plasma physics. Till date, these beams have been generated using linear optical elements. Here, we show a new way of generating HGBs by three-wave mixing in a nonlinear crystal. Based on nonlinear interaction of photons having OAM and conservation of OAM in nonlinear processes, we experimentally generated ultrafast HGBs of order as high as 6 and power >180 mW at 355 nm. This generic concept can be extended to any wavelength, timescales (continuous-wave and ultrafast) and any orders. We show that the removal of azimuthal phase of vortices does not produce Gaussian beam. We also propose a new and only method to characterize the order of the HGBs.