Methods and systems for studying microscopic particles are provided. An optical
trap for a selected microscopic particle can be formed with a laser beam at a first
power level. The laser beam can have a variable power level associated therewith.
The variable power level can be increased to a second power level. The laser beam
at the second power level can produce Raman scattering signals. The second power
level can provide sufficient excitation energy to the selected microscopic particle
to produce Raman scattering signals and the second power level is higher than the
first power level. A Raman spectrum can be detected from the Raman scattering signals
produced by the laser beam at the second power level.
