Imaging Model
Applying the 4F optical correlator design,* the probe laser power at the image plane is
??(x,y,t) is the phase shift due to the photothermal effect
The photothermal perturbation is assumed faster than the novelty filter response time.
The model predicts that an image of the photothermal phase shift can be obtained from image processing:
- The object-probe beam is an infinite-extent plane wave.
- The Fourier-transformed beam is a delta function at the conjugate plane.
- The BaTiO3 transmission is not affected by the phase-shifted beam.