A wavefront correction system using a dual frequency liquid crystal
spatial light modulator to vary phase relationships of a wavefront is
disclosed. A light beam from the dual frequency liquid crystal spatial
light modulator can be split into a reference beam and a plurality of
measurement beams to enhance a speed and/or accuracy of phase
measurement. A temperature of the dual frequency liquid crystal spatial
light modulator can be sensed to facilitate temperature control and/or
temperature compensation, so as to enhance the accuracy associated with
use of the crossover frequency used to control the dual frequency liquid
crystal spatial light modulator.