Tight focusing properties of vector polarized partially coherent vortex beams

Yaodan Hu; Xiahui Tang; Chenhao Wan; Yu Xiao; Gang Xu; Youyou Hu; Cong Hu; Jie Cheng; Ping Wang

doi:10.1117/12.2641887

16 December 2022 Tight focusing properties of vector polarized partially coherent vortex beams

Yaodan Hu, Xiahui Tang, Chenhao Wan, Yu Xiao, Gang Xu, Youyou Hu, Cong Hu, Jie Cheng, Ping Wang

Proceedings Volume 12312, Advanced Laser Processing and Manufacturing VI; 123120C (2022) https://doi.org/10.1117/12.2641887
Event: SPIE/COS Photonics Asia, 2022, Online Only

Abstract

Aiming at tightly focusing vector polarized partially coherent vortex laser beams, this paper introduced a new kind of vortex beams, named radially polarized multi-Gaussian Schell-model (MGSM) power-exponent-phase vortex beam (PEPVB). Based on the vectorial diffraction theory, this work theoretically and numerically investigated the tight focusing properties of radially polarized MGSMPEPVB passing through a high numerical aperture objective lens. Thus, we analyzed the impact of topological charge, power exponent, beam index and coherence length on the intensity of focal zone. We discovered that by increasing beam index, the intensity distribution of focal plane gradually changed from Gaussian to flat-top. Especially, when the power exponent was a non-negative fraction close to 1, regardless of whether the topological charge was an integer or not, the circular symmetry of the focused spot at focal plane would be destroyed, showing a non-uniform and asymmetric central dark core optical intensity distribution. Besides, the value of the fractional part of the topological charge would make the hollow structure of the central dark core fully open due to the introduction of power-exponent phase, which is an improvement over the tight focusing properties of radially polarized MGSM vortex beams. This work has clearly demonstrated that by changing the values of topological charge, power exponent, beam index and coherence length, the special focal spot structures with different intensity distributions including flat-top beam and irregular hollow beam can be obtained, which have many potential applications in laser machining and particle capturing such as manipulation of certain irregular microparticles.

Conference Presentation

Citation Download Citation

Yaodan Hu, Xiahui Tang, Chenhao Wan, Yu Xiao, Gang Xu, Youyou Hu, Cong Hu, Jie Cheng, and Ping Wang "Tight focusing properties of vector polarized partially coherent vortex beams", Proc. SPIE 12312, Advanced Laser Processing and Manufacturing VI, 123120C (16 December 2022); https://doi.org/10.1117/12.2641887

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