Ghost imaging and ghost diffraction with pseudo-thermal light generated by means of a programmable SLM

Abstract

Ghost imaging and ghost diffraction are techniques in which information about the object or about its diffraction pattern is extracted by measuring the correlation between a reference beam and a beam that passes through the object. Although first experiments were carried on by using entangled photons, it was demonstrated that this technique can be performed by splitting incoherent pseudo-thermal radiation such as that obtained with a laser passing through a moving diffuser. In this work we implemented the use of a programmable phase spatial light modulator (SLM) in order to replace the rotating ground glass. In this way the random phase distributions obtained from the moving diffuser can be emulated by displaying onto the SLM different realizations of a random function with uniform distribution. Based on the programmability of the modulator we have studied the influence of diverse parameters such as speckle size or phase distributions in the final image quality. We carry on the experiment for two different cases ghost imaging and far field ghost diffraction.