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Full-Text Articles in Physical Sciences and Mathematics

Spectral Broadening Effects On Pulsed-Source Digital Holography, Steven A. Owens, Mark F. Spencer, Glen P. Perram Aug 2023

Spectral Broadening Effects On Pulsed-Source Digital Holography, Steven A. Owens, Mark F. Spencer, Glen P. Perram

Faculty Publications

Using a pulsed configuration, a digital-holographic system is setup in the off-axis image plane recording geometry, and spectral broadening via pseudo-random bit sequence is used to degrade the temporal coherence of the master-oscillator laser. The associated effects on the signal-to-noise ratio are then measured in terms of the ambiguity and coherence efficiencies. It is found that the ambiguity efficiency, which is a function of signal-reference pulse overlap, is not affected by the effects of spectral broadening. The coherence efficiency, on the other hand, is affected. As a result, the coherence efficiency, which is a function of effective fringe visibility, is …


Phase Gradient Algorithm Method For 3-D Holographic Ladar Imaging, Jason W. Stafford, Bradley D. Duncan, David J. Rabb Aug 2016

Phase Gradient Algorithm Method For 3-D Holographic Ladar Imaging, Jason W. Stafford, Bradley D. Duncan, David J. Rabb

Bradley D. Duncan

3-D holographic ladar uses digital holography with frequency diversity to add the ability to resolve targets in range. A key challenge is that since individual frequency samples are not recorded simultaneously, differential phase aberrations may exist between them making it difficult to achieve range compression. We describe steps specific to this modality so that phase gradient algorithms (PGA) can be applied to 3-D holographic ladar data for phase corrections across multiple temporal frequency samples. Substantial improvement of range compression is demonstrated with a laboratory experiment where our modified PGA technique is applied. Additionally, the PGA estimator is demonstrated to be …


Phase Gradient Algorithm Method For 3-D Holographic Ladar Imaging, Jason W. Stafford, Bradley D. Duncan, David J. Rabb Jun 2016

Phase Gradient Algorithm Method For 3-D Holographic Ladar Imaging, Jason W. Stafford, Bradley D. Duncan, David J. Rabb

Electro-Optics and Photonics Faculty Publications

3-D holographic ladar uses digital holography with frequency diversity to add the ability to resolve targets in range. A key challenge is that since individual frequency samples are not recorded simultaneously, differential phase aberrations may exist between them making it difficult to achieve range compression. We describe steps specific to this modality so that phase gradient algorithms (PGA) can be applied to 3-D holographic ladar data for phase corrections across multiple temporal frequency samples. Substantial improvement of range compression is demonstrated with a laboratory experiment where our modified PGA technique is applied. Additionally, the PGA estimator is demonstrated to be …