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Updated: Jul 15, 2025
13:02
Fabrication of 1-D Photonic Crystal Cavity on a Nanofiber Using Femtosecond Laser-induced Ablation
Published on: February 25, 2017
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Twisted moiré photonic crystal enabled optical vortex generation through bound states in the continuum
Tiancheng Zhang1, Kaichen Dong2,3,4,5,6, Jiachen Li1,7
1Applied Science and Technology Graduate Group, University of California, Berkeley, CA, 94720, USA.
Nature Communications
|September 27, 2023
Summary
Twisted bilayer photonic crystals enable robust optical vortex generation by coupling bound states to free space. This moiré photonics approach offers new ways to control light
Area of Science:
- Photonics
- Condensed Matter Physics
- Moiré Physics
Background:
- Moiré physics emerges from twisted layered crystals, leading to chiral phenomena.
- Chiral phenomena include chiral phonon and photon generation.
- Bound states in the continuum (BIC) are modes localized in photonic crystals.
Purpose of the Study:
- To identify and formulate a twist-enabled coupling mechanism in twisted bilayer photonic crystals (TBPC).
- To investigate the generation of optical vortices with controllable topological orders.
- To analyze the robustness of optical vortex generation in TBPCs.
Main Methods:
- Theoretical formulation of twist-enabled coupling.
- Quantitative analysis of coupling between BIC modes and non-local modes.
- Investigation of radiation characteristics in the far field.
Main Results:
- A non-trivial twist-enabled coupling mechanism connecting BIC modes to free space was identified.
- Twisted bilayer photonic crystals generate optical vortices with odd and even topological orders.
- Optical vortex generation is robust against geometric disturbances.
Conclusions:
- TBPCs provide a novel platform for well-defined optical vortex generation.
- This work offers a new approach to manipulating photon angular momentum.
- The findings broaden moiré photonics and enable applications in optical information processing and optical tweezers.
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