Study of laser speckles in the presence of spherical aberration

High resolution displacement detection by speckle pattern analysis : accuracy limits in linear displacement speckle metrology

“…Aberrations appear when the acquisition of optical signals by imaging under oblique observation is done. Often, a deformation of the speckle field can be observed where the characteristic speckle size varies over the field of view [13]. This is also the case in our measurement system.…”

Effect of optical aberration on Gaussian laser speckle

“…When there are many independent scatters at the object field contributing to the field at an image point, or equivalently, the correlation length of the object field is much smaller than the effective extent of the coherent point spread function (PSF) in object space, R g and I g obey Gaussian statistics, which follows from the central limit theorem. The resulting variation of image irradiance is known as Gaussian speckle [5,10]. If R g and I g are governed by circular Gaussian statistics, where approximately the Airy disk diameter for fully developed speckle [5].…”

“…However, Stetson observed that lens aberrations affect speckle photography [8,9]. Bahuguna et al demonstrated that the effect of spherical aberration to speckle from a strong diffuser is ignorable, and only speckle generated from a weak diffuser is dependent on spherical aberration [10,11]. However, his analysis is confined to heuristic explanations using geometrical ray techniques without theoretical descriptions.…”