Abstract

The development of the single-beam gradient-force radiation pressure trap for microscopic dielectric particles has led to a range of biomedical and related applications.^1-5 However, the conventional gradient-force trap for high-index particles (n_p > n₀) has some limitations. For example, trapped particles are susceptible to optical damage via absorptive heating because the center of the trap is located in the high-intensity focal region of the beam. Also, multiple particles maybe attracted into the same trap; thus, isolating a single particle requires dilute samples. What is more, it is difficult to trap low-index particles using a conventional gradient-force trap. To circumvent these limitations, various schemes have been proposed.^6-8

© 1996 Optical Society of America