Optical Manipulation along an Optical Axis with a Polarization Sensitive Meta-Lens

Area of Science:

• Optics and Photonics
• Nanotechnology
• Biophysics

Background:

• Precise manipulation of small objects using focused laser beams is crucial for various scientific applications.
• Conventional optical tweezers, while effective, face limitations in miniaturization and integration within fluidic systems.
• There is a growing demand for compact trapping devices compatible with microfluidic environments.

Purpose of the Study:

• To demonstrate a plasmonic metasurface-based lens for stable, multi-center optical trapping along the optical axis.
• To enable precise control over particle position using light polarization.
• To develop a compact, integrated system for optomechanical manipulation in fluidic devices.

Main Methods:

• Fabrication of a plasmonic polarization-sensitive metasurface lens with nanoscale patch antennas.
• Integration of the metasurface lens within a fluidic cell.
• Utilizing incident light polarization to control particle position via interaction with antennas.
• Employing a particle-tracking algorithm with an integrated fluorescent module to map optical potentials.
• Demonstrating axial manipulation of a bead along a 4 μm line.

Main Results:

• The bifocal Fresnel meta-lens successfully created multiple stable trapping centers along the optical axis.
• Particle position was precisely controlled by altering the incident light's polarization.
• The device enabled axial manipulation of a trapped bead over a 4 μm distance, overcoming limitations of standard diffractive elements.
• Optical potentials were accurately mapped using the particle-tracking algorithm.

Conclusions:

• Plasmonic metasurface lenses offer a promising platform for advanced optomechanical manipulation.
• The developed bifocal Fresnel meta-lens provides enhanced control over particle positioning in three dimensions.
• This technology holds significant potential for lab-on-a-chip applications, including particle sorting and transport.