An imaging fiber-based optical tweezer array for microparticle array assembly

In this letter, we present a method to generate and regenerate arrays of microspheres by optically trapping through optical imaging fiber bundles. In this method, a laser beam is coupled into the proximal end of an optical fiber bundle, and the light energy is distributed across the face of the fiber. Each illuminated individual fiber in the array propagates light to the distal face of the bundle, where light focusing elements at the end of each fiber focus the laser light and form optical traps. These optical traps are capable of capturing and arraying microspheres in parallel. The number of optical traps is determined by the number of fibers in the optical fiber bundle and is capable of creating a dense array (∼5×104 traps/mm2) of optical tweezers.