Dynamic axial stabilization of counter-propagating beam-traps with feedback control

Area of Science:

• Optical physics
• Biophysics
• Nanotechnology

Background:

• Counter-propagating (CP) optical trapping offers advantages like increased working distance and reduced aberrations.
• Axial trapping performance in CP geometries is often limited by wave propagation effects of opposing beams.
• Existing methods struggle with precise axial force control, hindering practical applications.

Purpose of the Study:

• To develop a dynamic method for controlling axial forces in CP optical trapping.
• To overcome the limitations imposed by wave propagation on axial trapping performance.
• To demonstrate real-time feedback stabilization for enhanced axial trapping.

Main Methods:

• Utilizing computer-vision object tracking to monitor axial particle position.
• Implementing software-based feedback control for dynamic axial force stabilization.
• Conducting proof-of-concept experiments with various particle sizes and a cell colony model.

Main Results:

• Achieved real-time rapid repositioning of trapped particles.
• Demonstrated strongly enhanced axial trapping for multiple particles of varying sizes.
• Showcased adaptability for real-time reconfigurable feedback-trapping of a dynamically growing structure.

Conclusions:

• The proposed dynamic feedback method effectively overcomes axial performance constraints in CP optical trapping.
• This technique enhances experimental versatility and robustness against perturbations like laser fluctuations and vibrations.
• The approach is adaptable for complex systems, including mimicking biological processes like cell division.