Fig. 1: Principle of super-resolution acousto-optic imaging (AOI) via speckle fluctuations and numerical results.
From: Acousto optic imaging beyond the acoustic diffraction limit using speckle decorrelation
a Schematic of the experimental setup: An AOI setup is equipped with a rotating diffuser for producing controlled speckle fluctuations. An object hidden inside a scattering sample is imaged by scanning a focused ultrasound beam (in orange) over the object, and recording the ultrasound-modulated light power at each position. b At each position of the ultrasound focus, the fluctuations of the ultrasonically modulated light power due to the diffuser rotation (speckle decorrelation) are recorded. These are statistically analyzed to provide super-resolved AOI images (c–f). c Schematic depiction of the source of AOI fluctuations: at each position of the ultrasound focus (orange), different speckle realizations lead to different ultrasound-modulated power. d A simulated image produced with the average detected signal at each position provides a conventional AOI image resolution. e A simulated image produced from the second-order cumulant (variance) of the fluctuations at each position provides a \(\sqrt{2}\) improved resolution without deconvolution. f The simulated third-order cumulant image provides a \(\sqrt{3}\) improved resolution without deconvolution.
