Wavefront sensing and control are the component-level technologies that power active and adaptive optical systems. As its name suggests, wavefront sensing provides a means of measuring and comparing the wavefront actually found within an optical system with the ideal. Wavefront sensing can also be employed as a means of fingerprinting an optical system, i.e. retrieving the system's nominal optical prescription as well as indicating the origins of observed aberrations. Wavefront control is the means by which inputs obtained from a wavefront sensing capability are transformed into changes in deformable or otherwise reconfigurable elements within an optical system, bringing the measured wavefront into closer conformance with the ideal.

Wavefront sensing and control have become key technology elements of all extremely high performance optical systems, including those used for stellar interferometry, high contrast imaging and adaptive and active optical systems.