Chinese Optics Letters, Volume. 23, Issue 7, (2025)

Optical Orbital Angular Momentum Transformation Based on Nonlinear Forked Gratings [Early Posting]

Li Yilin, Xu Tianxiang, Zhao Ruwei, Liu Shan, Sheng Yan
Author Affiliations
  • Ningbo University
  • Key Lab Photoelect Detect Mat
  • Australian National University
  • show less

    We fabricated a three-dimensional nonlinear photonic crystal in a Sr0.61Ba0.39Nb2O6 (SBN) crystal using femtosecond laser direct writing of ferroelectric domain structures. The crystal features three layers of fork-shaped gratings, each oriented differently. These gratings convert an incident vortex beam into a second-harmonic Gaussian beam in specific directions. By altering the vortex beam's topological charge, we can control the emission direction of the second-harmonic beam, enabling flexible, all-optical switching and manipulation. This work provides a foundation for controlling photon angular momentum in nonlinear optical frequency conversion processes.

    Paper Information

    Manuscript Accepted: Feb. 10, 2025

    Posted: Feb. 21, 2025

    DOI: 10.3788/COL202523.071901