High Trap Stiffness Microcylinders for Nanophotonic Trapping

Area of Science:

• Photonics
• Materials Science
• Nanotechnology

Background:

• Nanophotonic waveguides facilitate on-chip optical trap arrays for high-throughput manipulation.
• Enhanced trapping force is crucial for expanding the capabilities of these optical trapping devices.

Purpose of the Study:

• To develop high refractive index cylindrical trapping particles for improved optical trapping.
• To investigate fabrication methods and trapping properties of silicon nitride (Si₃N₄) microcylinders.

Main Methods:

• Fabrication of silicon nitride (Si₃N₄) microcylinders using cleaving and lift-off methods.
• Characterization of trapping properties using the nanophotonic standing-wave array trap (nSWAT) platform.
• Comparison of Si₃N₄ microcylinders with polystyrene microspheres.

Main Results:

• Si₃N₄ microcylinders achieved a 3- to 6-fold increase in trap stiffness compared to polystyrene.
• Tunable microcylinder geometry was achieved through both fabrication processes.
• The lift-off method produced ultrasmooth microcylinder end surfaces.

Conclusions:

• Fabricated Si₃N₄ microcylinders offer significant trapping enhancement for nanophotonic waveguide applications.
• Tunable geometry and surface properties make these microcylinders versatile for high-force optical trapping.
• These advancements pave the way for broader applications in high-throughput nanophotonic manipulation.