Digital holographic tomograph: the tool for microelements investigation

摘要

In order to control performance of complex amplitude microelements it is necessary to receive information about amplitude and phase distribution of the field at each point (x,y,z) of the microelement under investigation. Digital holographic tomograph DHT proposed by our group permits in principle to investigate amplitude, phase and amplitude-phase objects. The capability of registration of several angular views of the object during one registration is the basic advantage of DHT. This is performed by a multiple pass arrangements and later by holographic reconstruction of an object at different distances. It decreases significantly the number of registered images used for determination of 3D amplitude and phase distribution in measurement volume, and may in future shorten significantly the measurement time or even allow for tomographic analysis of dynamic media. The analysis of tomographic algorithm best suited for 3D reconstruction based on a few non-evenly captured phase information is given. Numerical reconstruction of symmetrical phase microobject using DHT is presented. For numerical holographic reconstruction of the object the plane wave approximation method was applied. The numerical experiment has proven the possibility of reconstruction of phase for several different reconstruction distances for a certain class of objects and its application for tomographic reconstruction.