Optical tweezers with multiple optical forces using double-hologram interference

In earlier work, we introduced new ways of generating a series of interference patterns formed from Laguerre-Gaussian (LG) beams, which are being used as advanced optical tweezers in creating and manipulating three-dimensional structures. In this work, we have succeeded in demonstrating, for the first time to our knowledge, double LG and LG beams with a Gaussian-beam interference using a Michelson interferometer. We have been able to observe LG interference of unequal azimuthal charge by using just two holograms. This is a new type of optical tweezers because the tweezers have the ability to transfer orbital angular momentum, spin angular momentum, and optical gradient force simultaneously to microparticles. This provides a great opportunity for investigating the force interaction within a single laser beam. (C) 2003 Optical Society of America.