On-Chip Optical Trapping with High NA Metasurfaces.

Area of Science:

• Optics and Photonics
• Nanotechnology
• Biophysics

Background:

• High numerical aperture (NA) microscope objectives are standard for optical trapping.
• Photonic metasurfaces offer miniaturized, integrated solutions for beam manipulation.
• Developing metasurfaces for optical trapping requires precise design and fabrication.

Purpose of the Study:

• To design, fabricate, and characterize photonic metasurfaces for optical trapping.
• To evaluate the performance of metasurfaces against conventional microscope objectives.
• To explore the scalability and versatility of metasurface-based optical tweezers.

Main Methods:

• Design and fabrication of optical metasurfaces with NA up to 1.2.
• Characterization of trapping stiffness and performance.
• Analysis of metasurface dimensions' impact on trapping efficiency.
• Demonstration of multisite optical tweezers for extended objects.

Main Results:

• Metasurfaces achieved NA up to 1.2 and trapping stiffness > 400 pN/μm/W.
• Performance comparable to high-NA microscope objectives.
• Efficient trapping demonstrated with metasurfaces as small as 0.001 mm².
• Successful design of multisite optical tweezers for extended objects.

Conclusions:

• Photonic metasurfaces provide a viable, integrated alternative for optical trapping.
• Metasurface performance is scalable and adaptable for various trapping applications.
• This platform enables advanced optical manipulation with miniaturized devices.