Origin of vortex harmonic radiation from indium tin oxide thin films
Abstract
two-color field, is numerically investigated by solving the full-wave Maxwell equations with a nonlinear Kerr response. We show that the orbital angular momentum of the emitted harmonics provides a direct fingerprint of competing multiphoton pathways, because distinct photon-combination channels map onto harmonics with distinct topological charges and spatial profiles. For the fifth- and seventh-order harmonics, pathway competition is revealed through the evolution of intensity and spiral-phase structures with varying two-color amplitude ratios. Moreover, the ENZ regime is found to not only enhance harmonic generation but also preserve the topological stability of the emitted nonlinear modes.
Fields of Study & Subjects
ZnO doping and properties
Random lasers and scattering media
Spectroscopy and Quantum Chemical Studies
Publication details
- Journal / source
- Optics Letters
- Publisher
- Optica Publishing Group
- Volume
- 51
- Issue
- 11
- Pages
- 3136–3136
- Publication date
- 7 May 2026
- Language
- EN