  Precise control of particle positioning is desirable in many optical
propulsion and sorting applications. Here, we develop an integrated platform
for particle manipulation consisting of a combined optical nanofiber and
optical tweezers system. Individual silica microspheres were introduced to the
nanofiber at arbitrary points using the optical tweezers, thereby producing
pronounced dips in the fiber transmission. We show that such consistent and
reversible transmission modulations depend on both particle and fiber diameter,
and may be used as a reference point for in-situ nanofiber or particle size
measurement. Therefore we combine SEM size measurements with nanofiber
transmission data to provide calibration for particle-based fiber assessment.
We also demonstrate how the optical tweezers can be used to create a particle
jet to feed a supply of microspheres to the nanofiber surface, forming a
particle conveyor belt. This integrated optical platform provides a method for
selective evanescent field manipulation of micron-sized particles and
facilitates studies of optical binding and light-particle interaction dynamics.
