Manipulation of microparticles in colloidal liquids by Z-scan-based optical trapping

摘要

Manipulation of microparticles in colloidal liquids by using Z-scan-based optical trapping is systematically investigated. A physical model for the creation and annihilation of ordered structures in Z-scan-based optical trapping is presented theoretically and verified experimentally. Disordered, ordered, and intermediate states appearing in Z-scan trapping experiments are discussed and the conditions for realizing phase transition and observing self-induced transparency are clarified. We experimentally demonstrate the high quality and good stability of the formed structures, the sequential trapping of individual microparticles, and the multiple trapping processes. The dependence of the quality of the formed structures on trapping power, scanning speed, and the size and material of microparticles are identified.