1. A method of performing 3-D holographic microscopy of an optically trapped structure, comprising the steps of: providing an optical microscope; generating a laser beam having an associated imaging wavelength input to the inverted optical microscope; generating a plurality of optical traps with wave fronts of a trapping laser beam having a phase only hologram encoding a desired optical trapping pattern and the trapping laser beam having an associated trapping wavelength; and providing an objective lens for the inverted optical microscope, the objective lens both projecting the plurality of optical traps and collecting in-line holographic images of the trapped structure; and providing images of the trapped structure to a CCD camera for three-dimensional holographic microscopy of the trapped structure.