Off-axis laser interferometry

The off-axis method is an origination technique where a laser beam is split into two beams: an object and a reference beam. The object beam illuminates the object/artwork and is scattered onto a photoresist. The reference beam is directed onto the photoresist from the same side but at a different angle (off-axis). The two beams meet and overlap at the photoresist, generating an interference pattern which, in essence, provides a three-dimensional holographic record of the object.