Space gating for multiple scattering suppression: a step toward deep-tissue phase imaging
ABC 2018
Conventional imaging scheme, relying on a ballistic wave, is severely compromised when applied to a multiply scattering medium. To mitigate the effect, a typical approach has been to distinguish and reject a multiply scattered wave in a time domain using a time-gating and/or coherence-gating method. Here, we present a new gating scheme based on the acousto-optic effect that rejects the multiply scattered wave in a ‘space’ domain, more specifically, at the object plane. This method improves the ratio of the ballistic wave to the multiply scattered wave by more than ~100 times and enables imaging ‘inside’ an acoustic focus with an optical resolution through a scattering medium whose thickness is even 25 times thicker than the scattering mean free path.