A monitoring system and method are presented for use in monitoring a target. The monitoring system comprises: an input utility for receiving input data comprising measured data indicative of optical response of the target measured under predetermined conditions and comprising phase data indicative of a two-dimensional profile of full phase of the optical response of the target in a predetermined two-dimensional parametric space including a two-dimensional range in which said target exhibits phase singularity; an analyzer module for processing said measured data and extracting at least one phase singularity signature of the target characterizing the target status, the phase singularity signature being formed by a number N of phase singularity points, each corresponding to a condition that the physical phase continuously accumulates a nonzero integer multiple m of 2π around said point.