The vibrations of a surface can be measured by interfering a laser beam
reflected from a vibrating surface with another beam and measuring the
phase or frequency difference between the two beams.
Two seperate lasers are used. One laser beam excitese the molecules of
the object and a second "doughnut" laser beam depletes all but the
molecules at its middle before they are able to flouresce.
Optical Vortices for Data Transfer
An optical vortex can have an infinite number of states and could be used
to transfer data at a much faster rate than with binary encoding.
Generating Ince-Gauss beams
A curved output coupler of a laser cavity has to be shifted and
tilted off its original axis of curvature as explained here. Could be interesting to try.
A laser microphone could be built based on a laser doppler vibrometer, or
refelecting a beam of the vibrating surface and onto a photodetector.
Generating Airy Beams with
Generating Beam Modes with an