Fizeau interferometry has come a long way in the last decade. Driven by the need to qualify smaller features and mid-spatial frequency content, laser interferometers have been developed with extraordinary lateral resolution capability. But, resolution capability is much more than the pixel count of the sensor.

This webinar explores the drivers for high-resolution interferometry and the methods to reliably qualify an interferometer's ability to resolve lateral features – known as the Instrument Transfer Function (ITF).

This webinar includes:

  • Sources of mid-spatial frequencies in optical surfaces and the impacts on end-use optical systems.
  • Interferometer response to surface information as a function of spatial frequency.
  • How to reliably qualify and quantify the ITF of an interferometer to ensure the spatial frequency response is appropriate for the metrology it is intended to provide.

Technical papers cited in this webinar:

  • Coherent phase transfer function degradation due to wave aberrations of a laser Fizeau interferometer
  • Interpreting interferometric height measurements using the instrument transfer function
  • Lateral resolution and instrument transfer function as criteria for selecting surface metrology instruments