Microparticle trapping and manipulation by optical force in double coupled ring resonator (DCRR) via wavelength tuning

Microparticle trapping and manipulation using the optical force in double coupled ring resonator (DCRR) through wavelength tuning is reported in this paper. The DCRR consists of two coupled identical rings, and a waveguide that is side-coupled to the two rings. The microparticles are propelled by optical radiation force and trapped by optical gradient force, which are both generated by the evanescent field around the ring resonators. The different directions of relevant radiation forces on a polystyrene particle with diameter of 0.5 μm are analyzed at wavelengths of 1.567 μm, 1.569 μm, 1.572 μm, and 1.577 μm, which correspond to different particle moving directions. This versatile system has lots of potential applications in biological or chemical areas, such as micro-drug delivery, single cell manipulation, or micro-reactant transportation.