ABSTRACT
A precise computational integration of the Helmholtz equation was performed for laser propagation of an electromagnetic wave with no approximations or linearization. This computation integration was performed using 64-bit processors. This is illustrated for a uniform monochromatic beam from a circular aperture that has a uniform intensity. It predicts many Arago spots and near-field intensity fluctuations for a large ratio of aperture size to wavelength and converges to the usual Airy pattern in the far field.
ABSTRACT
An optimal filter algorithm for adaptive optics provides a powerful method for phase correction for propagation through the Earth's turbulent atmosphere involving anisoplanatism. In the new algorithm the outward phase correction is the sum of the product of a weighting function (the optimal filter) and all the wave-front measurements at the pupil, greatly improving the Strehl ratio. Two simplified cases are presented for illustration: (1) a collimated beam traversing a layer of uniform isotropic turbulence (angle anisoplanatism) and (2) focus anisoplanatism. It compares favorably with tomographic techniques. The technique can be extended to the case of thick, strong turbulence in the far field of a subaperture of an adaptive optics system.
