Abstract
Optical pulling forces, which can pull objects in the source direction, have emerged as an intensively explored field in recent years. Conventionally, optical pulling forces exerted on objects can be achieved by tailoring the properties of an electromagnetic field, the surrounding environment, or the particles themselves. Recently, the idea of applying conventional lenses or prisms as photonic probes has been proposed to realize an optical pulling force. However, their sizes are far beyond the scope of optical manipulation. Here, we design a chiral metalens as the photonic probe to generate a robust optical pulling force. The induced pulling force exerted on the metalens, characterized by a broadband spectrum over 0.6 μm (from 1.517 to 2.117 μm) bandwidth, reached a maximum value of −83.76 pN/W. Moreover, under the illumination of incident light with different circular polarization states, the longitudinal optical force acting on the metalens showed a circular dichroism response. This means that the longitudinal optical force can be flexibly tuned from a pulling force to a pushing force by controlling the polarization of the incident light. This work could pave the way for a new advanced optical manipulation technique, with potential applications ranging from contactless wafer-scale fabrication to cell assembly and even course control for spacecraft.
Highlights
Optical manipulations utilizing the mechanical effect of light provide a contactless way to controlling the position of small objects
To gain more insight into the physical mechanisms for the optical pulling force (OPF), we simulated the condition, we could simplify Equation (2) as longitudinal optical force profiles for a metalens illuminated by the divergent left circularly polarized (LCP) and right circularly polarized (RCP)
OPF was achieved by enhancing the forward momentum for the case of previously proposed photonic probes, such as gain media [23,24,25] and plasmonic nanoparticles [44]
Summary
Optical manipulations utilizing the mechanical effect of light provide a contactless way to controlling the position of small objects. This phenomenon is attributed to the intensity gradient in the focused field, which can act as an optical trapping potential for confining the particles in three dimensions (3D). Such optical manipulation methods have become essential research tools, with wide-ranging applications in biophysics [1,2], nanotechnology [3,4], classical and quantum physics [5,6] and space science [7,8,9]. OPF can be generated through applying surrounding media with designed properties, such as nonlinear optical liquids [20], topological photonic crystal [21], and waveguide
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
