Orientation of One Micron Size Cubes Suspended in a Quadrupole Trap

摘要

Single cubes whose dimensions are of the order of one micrometer have been suspended in a quadrupole trap and oriented by using a laser beam with a non-uniform azimuthal intensity distribution. This is a major step forward in our program to measure the complete Mueller matrix of small cubes and to compare the results with theoretical calculations. The orientation phenomenon itself is very interesting and provides new research directions such as studies of the dynamics of gas-particle interactions. The ability to hold and hence also turn a small particle by optical means provides the possibility of spinning a non-absorbing particle at very high speeds. Future work in these areas as well as complete analysis of the torques and intensity distributions in the orientation process are being planned. The orientation scheme is being engineered to fit into our Mueller matrix measuring apparatus and data for oriented cubes will be obtained.