Researchers Unveil Universal Gray Optical Trap in Structured Light
A team led by Prof. Yao Baoli and Dr. Xu Xiaohao from the Xi’an Institute of Optics and Precision Mechanics (XIOPM) at the Chinese Academy of Sciences has disclosed the first-ever universal gray optical trap in structured light, capable of capturing nanoparticles without reaching intensity minima or maxima. Their research, published in Physical Review A, redefines the boundaries of optical trapping.
Optical traps, pioneered by Arthur Ashkin in the 1970s, have revolutionized fields like biology, physics, and engineering. Typically, these traps are either bright or dark and are positioned at intensity maxima or minima, akin to optical "prisons" with strictly defined conditions. However, Prof. Yao and Dr. Xu’s team has challenged this convention by demonstrating a gray optical trap that operates under less restrictive conditions.
The researchers developed a high-order multipolar gradient force model based on multipolar expansion theory. By suspending silicon particles in a structured, petal-shaped light field, they discovered that high-order multipolar gradient forces can trap the nanoparticles at suboptimal or subminimal optical intensities. This phenomenon, driven by the non-local weight patterns of optical intensity, results in a novel optical "twilight zone" or full gray optical trap.
"This discovery opens doors to more nuanced manipulation of nanoparticles," said Prof. Yao. "We’ve shown that it’s not just about the intensity peaks and troughs, but also about the shades in between."
The full gray optical trap highlights the impact of Mie resonances in optomechanics and promises compelling applications in future ultrasensitive nanoparticle cooling, steering, and sorting technologies. The research team is now exploring the broader implications of their discovery, paving the way for next-generation optomechanical systems.
Additional Information:
Yanan Zhang et al., Full gray optical trapping by high-order multipolar resonant gradient forces in structured light, Physical Review A (2024). DOI: 10.1103/PhysRevA.110.063517
Funding & Affiliation:
This work was supported by the Chinese Academy of Sciences and the National Natural Science Foundation of China. The research team comprises members from the Xi’an Institute of Optics and Precision Mechanics at the Chinese Academy of Sciences.
Disclaimer:
This content is intended for informational purposes only. It is not intended to provide medical, scientific, legal, investment, or professional advice.
Copyright Information:
Copyright 2024. All rights reserved.
Keywords: Optical traps, gray optical trap, structured light, optomechanics, multipolar gradient forces, nanoparticles.
