Abstract

The interaction between laser light and a microsphere leads to two related phenomena. One concerns radiation pressure induced by photon momentum changes, which has been utilized as laser trapping of a microparticle.^[1−3] The other is optical resonance within a microsphere, namely, light propagates in a circumferential manner to create a standing wave field. This resonance has been applied to lasing of a dye- doped particle.^[1] Hovewer, previous examples for lasing microspheres are limited to those for liquid droplets suspended in air and for particles attached to substrates. In this paper, we report simultaneous 3-D optical trapping and lasing of a dye-doped polymer latex particle in water, which makes it possible to precisely investigate dynamical and spectroscopical characteristics of a microspherical cavity. Furthermore, a trapped lasing particle can also be used as a movable small light source.

© 1992 IQEC