Optical tweezing of microparticles and cells using si-based optical phased arrays - Paper of the Day

           This paper presents the first demonstration of optical trapping and tweezing using an integrated optical phased array (OPA) system. The OPA system can focus light into a narrow beam that is 5 mm above the surface of a silicon photonics chip. This lets polystyrene microspheres and mouse lymphoblast cells be optically trapped and moved around. The authors first demonstrate trapping of polystyrene microspheres and calibrate the trap stiffness, showing it scales linearly with optical power. They then show that the position of the trap can be changed without using mechanical means by changing the wavelength of the laser that is being used. This lets the microspheres be squeezed in one dimension optically. Also, the authors use the OPA tweezers to demonstrate controlled deformation of mouse lymphoblast cells, the first such demonstration with single beam integrated optical tweezers. This work significantly expands the utility and compatibility of integrated optical tweezers by increasing the standoff distance and enabling active tweezing functionality, opening the door to a wider range of biological experiments.

Keywords:

Optical Phased Array (OPA), Optical Trapping, Optical Tweezers, Microplastics, Microspheres, Mouse Lymphoblast Cells, Polystyrene, Non-Mechanical Steering, Trap Stiffness, Standoff Distance