A new sensor for remote interferometry

In this paper we describe a new sensor for the direct holographic comparison of the shape of two objects where it is not necessary that both samples are located at the same place. In contrast to the wellknown incoherent techniques based on inverse fringe projection this new approach prefers a coherent mask that is overlayed to the sample object having different microstructure. The coherent mask is created by digital holography to enable the instant access to the complete optical information of the master object at any wanted place. The transmission of the digital master holograms to the relevant places is done with a broadband digital telecommunication network such as the Internet. The availability of the complete optical information of the master object in the form of its digital hologram offers two ways with respect to the comparison of its shape and/or deformation with those of a sample object having different microstructure: digital comparison of the respective phase distributions of the relevant digital holograms and analogue comparison of both holograms/interferogram by digital comparative holography.