Speckle interferometry phase determination using a single interferogram

This paper presents two methods for the phase determination using only one interferogram, that is two holograms for different states of an object. These methods are the interferometry by digital holography and method of spatial carrier in the primary fringes. They are well suited for transient phenomena because a minimum of two holograms is required. By electronic control of the acquisition camera both holograms can be recorded on the same target with a small time separation.