Abstract by Ellyse Taylor
Physics and Astronomy
Closeup Images of Microscopic Dust Particles Trapped in a Laser Beam by Photophoresis
Photophoretic trapping of small dust particles in a laser beam has recently found application in the creation of three-dimensional displays (somewhat like a hologram). A deeper understanding of the photophoretic force is needed to increase the speed at which particles can be swept around to form an image. We describe a setup that can characterize particle size, motion, and location as it is held near the laser focus. We use a microscope objective and video camera to document the complex phenomena in situ with an accuracy of a few microns.