A statistical treatment of speckle correlations as a function of the position of a moving object is shown to provide access to object information through thick and heavily scattering random media. Experiments for a patch-like object of varying size and for varying degree of background scatter are explained using a model, and an experimental study allows evaluation of key attributes. Given a sufficient signal-to-noise ratio, adequate coherence, and developed field statistics, measured speckle intensity patterns from a set of object positions can allow high-resolution imaging deep into an obscuring medium and the medium's scattering strength can be gauged quantitatively with calibration. This enables new opportunities in application domains such as optical sensing, material inspection, and deep tissue in vivo imaging.
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Theory of speckle intensity correlations over object position in a heavily scattering random medium
We present a general theory for optical imaging of moving objects obscured by heavily scattering random media. Measurements involve collecting a series of speckle intensity images as a function of the position of a moving object. A statistical average intensity correlation can be formed with the potential to provide access to microscopic and macroscopic information about the object. For macroscopic objects and translation distances that are both large relative to the wavelength, there is a clear method to invert measurements to form an image of the hidden object. Opportunities exist for super-resolution sensing and imaging, with far-subwavelength resolution. Importantly, there is no fundamental limit to the thickness of the background randomly scattering medium, other than the practical requirement of detecting an adequate number of photons and sufficient background scatter for developed Gaussian field statistics. The approach can be generalized to any wave type and frequency, under the assumption that there is adequate temporal coherence. Applications include deep tissue in vivo imaging and sensing in and through various forms of environmental clutter. The theory also provides another dimension for intensity interferometry and entangled state detection to the case with motion of the scatterer or emitter.
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- Award ID(s):
- 1909660
- PAR ID:
- 10518035
- Publisher / Repository:
- Physical Review A
- Date Published:
- Journal Name:
- Physical Review A
- Volume:
- 101
- Issue:
- 6
- ISSN:
- 2469-9926
- Page Range / eLocation ID:
- 063827
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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