Acousto-optic imaging using quantum memories in cryogenic rare earth ion doped crystals

Abstract

The interaction of ultrasound and light in biological tissues results in a small amount of the scattered light being shifted relative to the carrier frequency (typically 1 part in 108). We have developed an inherently efficient and low noise quantum memory based technique to selectively absorb these ultrasound tagged photons in a pair of atomic frequency combs, and recover them delayed in time as a photon echo. In this manner we have demonstrated record ultrasoundmodulated sideband-to-carrier discrimination (49dB). Further, we confirm that the technique is compatible with highly scattering samples, and present initial acoustic pulse tracking measurements. This strongly suggests the suitability of the technique for biological tissue imaging.