Compact Lateral Shearing Interferometer to Determine Continuous Wave Fronts

In this work we present a very compact implementation of a lateral shearing interferometer which makes use of the birefringent properties of a reflective liquid crystal spatial light modulator (SLM). The main advantage of this approach is its considerable tolerance against environmental disturbances and its high degree of flexibility. A great variety of lateral and/or radial shears can be realized without the requirement of moving parts. The setup can be used to determine continuous wave fronts reflected by coherently illuminated objects. Thus it is capable of acquiring 3D interferometric data in a very flexible and robust way. Experimental results are presented as an example of application. The lateral phase distribution of a disturbed wave front is recorded with the proposed interferometer.