Wavefront Sensing

 

Courtesy Lu Li, LOA

Imagine Optic wavefront sensors are based either on the so-called Hartmann or Shack-Hartmann technologies using respectively a 2D array of holes or of microlenses to sample the incoming beam. Each lens or hole projects an image onto the detector, its position being given by the local curvature of the wavefront (green dots). This kind of sensor provides measurements relative to a perfect wavefront, that corresponds to a set of reference positions for the projected sub-images (white dots). The wavefront of the incoming wave is determined from the deviations along both directions of the measured centroid positions compared to the reference positions.