Propagation and orbital angular momentum of vortex beams generated from a spiral phase plate-fiber

摘要

We report on the generation of vortex beams employing a spiral phase plate (SPP)-fiber, which is fabricated by directly imprinting an SPP on the tip of a single-mode optical fiber. The generated high-order Laguerre-Gaussian (LG(p,l)) modes with a radial number of p > 0 diverge quickly, thereby leaving the main LG(0,)(-1) mode in the far field. Employing 1D Fourier transform, the average orbital angular momentum is determined to be -0.989h per photon, close to the theoretically calculated value of ( )similar to-h. Such an SPP-fiber, offering a simple way to produce vortex beams, could be a promising candidate for applications in multi-dimensional optical trapping and material microstructure processing.