Complex Field Sensing and Control with Fiber-Array-Based Collett-Wolf Beacon for Navy Tactical HEL Applications

A scintillations and speckle-noise resistant complex field (optical wave amplitude and phase) sensing concept referred to here as Speckle-Average Phase Retrieval (SAPR) is proposed. The SAPR concept is based on the following Optonicus"innovations: (a) Mitigation of speckle noise by creating an auxiliary incoherent light source, directly on the target surface using rapid steering (dithering) of an auxiliary laser beam that is generated by a fiber-array based target illuminator system; (b) Complex field sensing with the Optonicus"multi-aperture phase reconstruction sensor that is based on a low-resolution lenslet array in the classical Shack-Hartmann arrangement and two high-resolution photo-arrays for simultaneous measurements of speckle-averaged pupil- and focal-plane intensity distributions which are used for retrieval of wavefront phase in a two stage process: phase reconstruction inside the sensor pupil sub-regions corresponding to lenslet sub-apertures, and recovery of sub-aperture averaged phase components (piston phases). Preliminary analysis demonstrates the efficiency of the SAPR approach in conditions of strong intensity scintillations, speckle-noise and presence of wavefront branch points. During the Phase I effort, the SAPR complex field sensing concept will be analyzed through extensive wave-optics numerical simulations. Different SAPR system architectures will be considered, evaluated, and optimized.