Coherent digital optics in Free space
Damien Kelly (Oryx Optics Ltd, Ireland)
A brief review of Fresnel digital holography is made. Some of the limitations of this technique are formulated theoretically and their implications discussed. A comparison of this technique (pro’s/cons’s) is made with iterative phase retrieval methods. A thought experiment is then introduced to further examine convergence problems in PR methods. Finally all of these optical techniques require the numerical calculation of the Fresnel transform. Hence, a tutorial on some of the computational challenges is presented.