{'fraction_non_alphanumeric': 0.010586319218241042, 'fraction_numerical': 0.0, 'mean_word_length': 5.943502824858757, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Digital holographic tomography for path-resolved turbulence measurements

We present a new technique combining digital holography and tomography to make path-resolved measurements of a turbulent air volume. An array of optical beams at different propagation angles is transmitted through the volume under test, interfered with a reference beam, and the resulting fringe patterns are all simultaneously recorded on a focal plane array. The complex field of each beam in the receiver pupil plane is recovered via digital Fourier processing and then tomographic reconstruction algorithms are applied to calculate wavefront error contributions from multiple planes along the beam path. Results are presented from a proof-of-concept laboratory experiment using phase screens to mimic the turbulence volume. Comparing the tomographic reconstructions to the known screen prescriptions, we successfully demonstrate accurate measurement of the phase distortions introduced in multiple planes. This ability to longitudinally resolve turbulence and isolate individual layers may benefit numerous applications including precision turbulent flow analysis in wind tunnels and adaptive optic compensation for free space optical communications.