Center for Relativistic Laser Science

2019 SPIE Photonics West

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 or coherence-gating method. Here, we present a new gating scheme based on the acousto-optic effect that rejects the multiply scattering 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 more than ~100 times and enables imaging ‘inside’ an acoustic focus with an optical resolution through a scattering medium of L/μs ~ 25 (μs is the scattering coefficient and L is the thickness of a scattering medium). We further discuss the noise suppression fidelity of our method in comparison with the conventional time-gating (or coherence-gating) method.