Mechanical effects of interference light field on dielectric microparticles

摘要

We demonstrate optical manipulation with micrometer-sized dielectric particles. Instead of well-known optical tweezers we use complex interference pattern (so-called optical landscape) to trap and confine polymer microspheres in maxima and minima of optical intensity. The optical pattern is created by interference of two or three beams, respectively, which results in interference fringes or hexagonal interference structure. Multiple beam setup uses spatial light modulator to divide incoming laser beam into several directions by diffraction on the phase grating. Small particles are trapped in maxima of intensity, while larger particles are attracted by neighbouring maxima and are confined in minima of intensity with their center.