Instantaneous Phase-Shift, Point-Diffraction Interferometer

Wavefront measurement is important in the manufacture of individual optical components and for the optimization of sub-assemblies in optical data storage. The trend towards short-wavelength, high numerical-aperture pickup systems predicates the need for active optical alignment during final assembly. Thus, a real-time measurement system capable of operation at blue wavelength and at high numerical aperture is of significant utility for the fabrication and test of next generation of optical data storage devices.

Point diffraction interferometry is a simple, self-referencing configuration to measure the wavefront quality of low temporal coherence optical beams. Significant research has been devoted to adapting phase-shift interferometric techniques to common path interferometry to enable high precision wavefront measurements.