Optical tweezers have been used to trap nanoscale dielectric particles using forces applied with focused laser beams. An electric field gradient at the beam waist draws particles to the center of the beam. Particles also experience a force in the direction of beam propagation, and thus tend to be situated slightly displaced from the beam waist along the direction of propagation. While conventional optical tweezers are useful in many applications, improvements are needed to expand the range of available applications, particularly for trapping particles <50 nm in size.