Optical manipulation and transport of microparticles on silicon nitride microring-resonator-based add-drop devices.

We demonstrate optical manipulation and transport of 1 microm sized polystyrene particles on silicon nitride microring-resonator-based add-drop devices in an integrated optofluidic chip. By tuning the input laser wavelength and upon certain resonance quality factors, we observe microparticles (i) transported to the throughput port, (ii) routed to the microring and trapped in round trips, and (iii) transported to the drop port. We investigate the microparticle velocity at various laser wavelengths and in various spatial regions of the devices with different resonance quality factors. Such a device can act as a particle add-drop filter for "particle circuits" in lab-on-a-chip applications.