Applications Of High Speed Pulsed-Laser Interferometry

Recently a new class of phase-shifting interferometers have been developed that allow us to measure optical phases with high temporal variations. A stationary diffraction grating plays the key role to split the input beam into 0, +1, and -1 orders and simultaneously to introduce a phase shift among the multiplexed beams. This simultaneous phase shift provides the capability for instantaneous measurement of optical wavefronts by using pulsed-lasers. The theoretical basis for the phase shifting interferometry will be introduced briefly. Also results of laboratory measurements will be shown for examples such as the wavefront quality of a pico-second pulsed-laser beam, surface figure measurement of an actuated deformable mirror, and the air turbulence induced by high pressure air flow at different temperatures and flow speeds.