Multiscale lensless visual position sensing by digital holography

International audienceVision is a powerful contact-less control method that is widely used in many domains of applications [1-3]. However, because of physical laws describing refractive imaging systems, major parameters (magnification, lateral resolution, depth of focus, working distance, field of observation) are tied with each other in a contradictory way. An increase in magnification leads to an improvement in lateral resolution at the detriment of other parameters and vice-versa. The only ways to improve all parameters simultaneously is to reduce the imaging wavelength or to increase the refractive index but, in practice, such solutions present several highly limiting constraints