## Numerical modeling of optical gradient traps using the vector finite element method

It has been established that under certain conditions microscopic dielectric objects can be trapped by a tightly focused laser beam. This phenomenon is commonly referred to as an optical gradient trap. The recently developed vector finite element method is used to visualize the interaction of the laser beam with the dielectric object and to quantitatively predict the optical trapping efficiency. The vector finite element method is an accurate and efficient approach when the incident beam wavelength is comparable to the object size, and it has the advantage that it can be used to model the trapping of arbitrarily shaped 3Dmore »