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UID:2025-10-16-anat-levin@cail.columbia.edu
DTSTAMP:20260823T060740Z
DTSTART:20251016T150000Z
DTEND:20251016T160000Z
SUMMARY:Vision Seminar: Anat Levin - Seeing Deep Inside Scattering Tissue 
 Using Efficient\, Noise-Robust Wavefront Shaping
LOCATION:620 CEPSR
DESCRIPTION:Scattering limits our ability to see inside biological tissue\
 , as light penetration is severely distorted by tissue components with var
 ying refractive indices. One promising method to overcome scattering aberr
 ation is wavefront shaping. This technique involves placing a spatial ligh
 t modulator (SLM) in the microscope's optical path to correct the wavefron
 t emitted from a point deep within the tissue. The goal is to bring light 
 photons from a single target point to a single sensor point\, despite tiss
 ue aberrations. This technique has the potential to revolutionize tissue i
 maging by enabling high-SNR imaging deep within scattering biological targ
 ets. However\, estimating wavefront-shaping modulations in practice is cha
 llenging\, since the modulations must be estimated in real time\, using no
 n-invasive feedback\, and under a low photon budget.\n\nIn the first part 
 of this talk\, I will discuss efforts to derive noise-robust score functio
 ns that can identify effective modulation corrections using non-invasive f
 eedback. I will review previous approaches and introduce a new\, simple\, 
 noise-robust method that uses confocal correction of both incoming and out
 going light with linear single-photon fluorescent excitation. We show that
  despite the fact that we are only measuring light outside the tissue and 
 have no direct way to measure how well light has focused inside the tissue
 \, maximizing the single-photon confocal intensity guarantees that we also
  focus all light into a spot inside the tissue.\n \nGiven a score function
 \, estimating the desired modulation becomes an optimization problem. Howe
 ver\, since the desired modulation depends on the unknown tissue structure
 \, typical optimization strategies involve slow sequential scanning\, wher
 e each modulation parameter is queried independently. In the second part o
 f this talk\, I will present a novel approach for rapid modulation optimiz
 ation. This method leverages optical computing ideas and uses the optical 
 system to directly measure the gradient of the score function\, allowing s
 imultaneous updates of all modulation parameters from a single measurement
 .\n\nhttps://cail.columbia.edu/events/2025-10-16-anat-levin
URL:https://cail.columbia.edu/events/2025-10-16-anat-levin
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