Abstract

Continuous-wave ultrasonic modulation of scattered laser light has been used to image objects in tissue-simulating turbid media for the first time.¹ We hypothesized that the ultrasound wave focused into the turbid media modulates the laser light passing through the ultrasonic focal zone. The modulated laser light collected by a photomultiplier tube reflects the local mechanical and optical properties in the focal zone. Buried objects in 5-cm thick tissue phantoms (absorption coefficient μ_a = 0.1 cm⁻¹, reduced scattering coefficient μ_s′ = 10 cm⁻¹) were located with millimeter resolution by scanning and detecting alterations of the ultrasound-modulated optical signal.

© 1996 Optical Society of America