Multi-topological charges vortex beam generator based on nonlinear bound states in the continuum with improvement of nonlinear conversion efficiency

Hang Xu; Hui Li; Qi Tan; Chunyu Song; Yating Zhang; Bo Wang; Jie Li; Jianquan Yao

doi:10.1117/12.2688659

26 November 2023 Multi-topological charges vortex beam generator based on nonlinear bound states in the continuum with improvement of nonlinear conversion efficiency

Hang Xu, Hui Li, Qi Tan, Chunyu Song, Yating Zhang, Bo Wang, Jie Li, Jianquan Yao

Author Affiliations +

Proceedings Volume 12775, Quantum and Nonlinear Optics X; 127751K (2023) https://doi.org/10.1117/12.2688659
Event: SPIE/COS Photonics Asia, 2023, Beijing, China

Conference Poster

Abstract

In the momentum space of bound states in the continuum (BIC), vortex configurations around the Γ-point are generated by the selection rules. The electric field distribution close to the BIC satisfies twofold rotational symmetry (C₂). Since the periodic structure of 2D photonic crystals (PhCs) supports the generation of odd harmonics, this characteristic provides an attractive approach for generating high-harmonic optical vortex (OV) beams with both left and right handedness. Also, the topological charge of OV beams generated by C_4v-symmetric PhCs can be further improved by an increase of structural symmetry. Moreover, since the nonlinear conversion efficiency of directly used PhCs is low, their practicability is limited. Here, a hexagonal arrangement of C_6v-symmetric 2D PhCs slab is selected. Through energy band selection, higher order fundamental and nonlinear OV beams can be generated, which can not only cover the topological charge of the C_4v-symmetric structure, but also generate more abundant topological charge. In addition, we improve the third-order nonlinear conversion efficiency by the mirror approach, which is 22 times greater than with the direct use of PhCs. This method can improve the channel capacity of OV generators based on BICs and make them more practical.

(2023) Published by SPIE. Downloading of the abstract is permitted for personal use only.

Citation Download Citation

Hang Xu, Hui Li, Qi Tan, Chunyu Song, Yating Zhang, Bo Wang, Jie Li, and Jianquan Yao "Multi-topological charges vortex beam generator based on nonlinear bound states in the continuum with improvement of nonlinear conversion efficiency", Proc. SPIE 12775, Quantum and Nonlinear Optics X, 127751K (26 November 2023); https://doi.org/10.1117/12.2688659

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available