Optical Surface Profiling Using Beamlet Deflection Method

Deflectometry and slope measurement techniques are being used for surface profiling and wavefront estimation. In present study a screen having multiple apertures of small size is inserted in the object path which is illuminated by a collimated and test wave. The beamlets are generated and its images at different image planes are used to compute the wavefront slope. These slopes are then used in reconstruction of the wavefront. The preliminary results of the investigations carried out on beamlet deflection technique to estimate the spherical, cylindrical and freeform wavefronts are presented. At longer image plane distances, the calculation of slope value is more accurate and hence the wavefront estimation.