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Abstract Optical vortex beams with helical phase fronts have immense potential to enhance data capacity due to the unbounded values of orbital angular momentum. Chip‐scale platforms for producing vortex beams are of paramount importance for a variety of applications. On the other hand, 2D materials with unique optical properties are essential for developing multifunctional ultrathin photonic devices. Here, anisotropic and temperature‐tunable second‐harmonic vortex beam generation is demonstrated with ultrathin ferroelectric niobium oxide dichloride (NbOCl2) fork holograms. The polarization‐resolved Raman measurements are performed on the NbOCl2crystal to understand the anisotropic behavior of the Raman modes. It is demonstrated that the anisotropic and temperature‐tunable second‐harmonic vortex beams can be generated regardless of the relative orientation of the fork gratings with respect to the crystallographic orientation of the NbOCl2flakes. Furthermore, the Curie temperature of the ferroelectric NbOCl2crystal is determined according to the measured temperature‐dependent second‐harmonic generation intensities. The results presented here create new opportunities for the development of advanced polarization‐sensitive and temperature‐switchable nonlinear photonic devices used for future applications in integrated photonic devices, quantum optical chips, and optical communication.
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This content will become publicly available on April 1, 2027
Generation of Anisotropic Second‐Harmonic Petal‐Like Beams with NbOBr 2 Holograms
The coherent superposition of two vortex beams with opposite topological charges gives rise to the formation of petal‐like beams with unique intensity profiles and azimuthal phase structures, offering great potential for various applications. Here, the generation of anisotropic second‐harmonic petal‐like beams is demonstrated using ultrathin niobium oxide dibromide (NbOBr2) holograms. The polarization‐dependent Raman measurements are conducted on the NbOBr2flake to reveal the anisotropic properties of the crystal. By imprinting the beam profile information of the superposed vortex beams on the designed NbOBr2holograms, highly anisotropic second‐harmonic petal‐like beams with different combinations of the topological charges of vortex beams are produced. The results demonstrated here provide a pathway toward the development of chip‐scale polarization‐sensitive functional optical devices for applications in optical communication, optical trapping, and quantum optics.
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- PAR ID:
- 10684370
- Publisher / Repository:
- Wiley
- Date Published:
- Journal Name:
- Advanced Photonics Research
- Volume:
- 7
- Issue:
- 4
- ISSN:
- 2699-9293
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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