Abbie E. Tippie

High-resolution synthetic-aperture digital holography with digital phase and pupil correction

A 218 mega-pixel synthetic aperture was collected by raster scanning a CCD detector in a digital holography imaging experiment. Frames were mosaicked together using a two-step cross-correlation registration. Phase correction using sharpness metrics were utilized to achieve diffraction-limited resolution.

Multiple-plane anisoplanatic phase correction in a laboratory digital holography experiment

We present results for a digital holography experiment with anisoplanatic image correction through two discrete planes of phase errors. Using a nonlinear optimization technique, we maximize a modified sharpness metric to solve for estimates of the phase errors in the system in the multiple planes where they physically exist. We show that correcting for phase errors in multiple planes gives a superior image to correction in one plane.

Phase-error correction for multiple planes using a sharpness metric

Phase errors in multiple planes create an anisoplanatic (space-variant) blur in an image. We show how phase errors in multiple planes can be corrected with the use of a sharpness metric for heterodyne or holographic imaging. We derive the theoretical framework necessary for this anisoplanatic imaging situation. A digital simulation and results are presented. We demonstrate the success of this nonlinear optimization technique for phase errors in two planes.

Weak-Object Image Reconstructions with Single-Shot Digital Holography

Weak object signals with less than one photoelectron per detector pixel can be recovered using off-axis digital holography. We show image reconstructions in simulation with a single exposure.

Sub-Aperture Techniques Applied to Phase-Error Correction in Digital Holography

We correct for phase errors in a synthetic aperture digital holography experiment using sub-apertures. Relative image translations from sub-apertures are used to estimate 7th order polynomial phases and reconstruct images with improved resolution.

Gigapixel synthetic-aperture digital holography

Building on the work of Goodman and Lawrence [1], we have extended digital holographic imaging to gigapixel scales with 2-D aperture synthesis. Sub-pixel registration algorithms were required to mosaic together thousands of arrays of data, and phase-error correction algorithms were required to correct for system instabilities.

Gigapixel Synthetic-Aperture Digital Holography: Sampling and Resolution Considerations

A gigapixel array is used for synthetic-aperture digital holography. Considering propagation and sampling requirements, a high-resolution image is reconstructed using sharpness metrics in combination with speckle-averaging independent realizations.

Phase error correction for multiple planes using sharpness metrics

Phase errors introduced in the object beam of a digital hologram degrade the image quality of the object. We present computer simulations showing the effect of multiple planes of phase errors in the propagation path. By using a nonlinear optimization technique to maximize sharpness metrics, we show results that account for aberrations in multiple planes and correct anisoplanatic blur. This paper demonstrates this technique for two and three phase screens.