Sub-Nyquist Coherent Imaging Using an Optimizing Multiplexed Sampling Scheme [Tips & Tricks]

Several techniques have been developed to overcome the limitation of sensor bandwidth for 2D signals [1] . Though compressive sensing is an attractive technique that reduces the number of measurements required to record information on a sparse signal basis [2] , [3] , recording information beyond the Nyquist frequency remains difficult when working with nonsparse signals. Given this constraint, this article focuses on the use of the physical bandwidth of a coherent signal in the complex form instead of its intensity form. The resulting trick combines holographic multiplexing with sampling scheme optimization to obtain the information in a 2D coherent signal from beyond the Nyquist frequency range. The prerequisites for understanding this article are a knowledge of basic algebra and the Fourier transform. Familiarity with holography is also beneficial.