We combine a radiation-pressure-based levitation system with a dual fiber, laser trapping system to demonstrate the potential of delivering single particles into the fiber trap. The forces versus position and the trajectory of the particle subjected to the laser beams are examined with an enhanced ray optics model. A sequence of video images taken from the experimental apparatus demonstrates the principle of particle delivery, trapping, and further manipulation.

An enhanced ray optics model is applied to the study of the optical levitation and trapping properties of a glass cubic object. It is found that for certain highly symmetric orientations simultaneous force and torque equilibrium can exist in the lowest-order TEM00 laser beam profile. For analytical purposes, the square surfaces of the cube are divided into two identical triangular surfaces, and the interaction of the rays with these triangular surfaces simplifies the computation of the total force and torque on the cube. The technique developed can easily be extended to the study of other regular or complex structures.

Long cylindrical objects have been observed to align their central axis with the propagation axis of the illuminating laser beam through the action of radiation-pressure-generated force and torque. A cylindrically shaped microactuator based on this principle and suitable for micromachine applications is examined theoretically. When four in-plane laser beams converging at a common point centered on the cylinder are used, the cylinder can be made to rotate about a pivot point. In one mode, smooth, continuous, and reversible rotation is possible, whereas the other cylinder can be step rotated and locked, similar to the operation of conventional stepping motors. The properties of the device are analyzed based on obtaining either a constant rotation rate with variable beam power levels or a quasi-constant rotation rate with constant beam power levels or on using a fixed beam sequence rate that matches the system parameters and produces smooth or stepped operation.