Abstract: A system capable of determining wavefront characteristics, such as air induced wavefront aberrations, includes a field programmable gate array (FPGA) device executing a phase diversity algorithm. The FPGA device can be a stand-alone device or comprise multiple FPGAs. The device receives an “in-focus” and an “out-of-focus” image having a known optical difference from that of the “in-focus” image. The device then performs as many phase diversity algorithm iterations as desired to reach an expression for the wavefront aberrations induced on the collected image data. The resulting wavefront data may be used to produce an enhanced image of the original image data. Example applications include remote sensors and targeting systems, and both passive imaging and active projection systems that compensate for wavefront anomalies.

Abstract: An optical field sensing system and an associated method are provided that are tolerant of scintillation. The system includes a wavefront sensor that measures gradients across a wavefront at a first resolution defined by the subapertures of the wavefront sensor. The system also includes an intensity sensor that measures the intensity across the wavefront at a higher resolution. The system further includes a wavefront processor that determines respective phases across the wavefront. In addition to the gradients and the intensity measurements, the wavefront processor may determine the respective phases based also upon the noise affiliated with the measurements. In this regard, the wavefront processor may determine the respective phases across the wavefront at least partially based upon the gradients as adjusted by weights that are based upon the intensity measured by the intensity sensor and are influenced by evidence of scintillation.

Abstract: A fiber optic phased array and control method are provided for controllably adjusting the phase and amplitude of the optical signals emitted by a plurality of fiber optic amplifiers to compensate for atmospheric turbulence. The fiber optic phased array also includes a sensor assembly for detecting: (i) the phase of the optical signals that are emitted by the fiber optic amplifiers, and (ii) both the phase and the amplitude of the optical signals that have been reflected by the target. The fiber optic phased array also includes phase modulators and a gain adjustment mechanism for altering the phase and the amplitude of the optical signals propagating along the fiber optic amplifiers to compensate for modifications in the phase and amplitude that will be introduced by atmospheric turbulence. Among other things, the amplitude control of the optical signals is not adversely effected by intensity nulls in the reflected wavefront.