Patent ID: 7733742

Claim:
An acousto-optic tomographic imaging method for an object comprising steps during which: (a) the vibration of a three-dimensional area of the object is generated by applying an acoustic wave exhibiting a certain acoustic frequency to the object, (b) an incident wave and a pump wave are generated by: generating an initial light wave with a light wave generating device, and splitting said initial wave into a first beam and a second beam; shifting the frequency of said first beam by a first frequency shift in order to generate the incident wave, shifting the frequency of said second beam by a second frequency shift in order to generate the pump wave, said second frequency shift being roughly equal to the sum of the first frequency shift and the acoustic frequency; (c) an incident light wave is applied to said object and a signal light wave is generated by travelling through the object and interacting with the three-dimensional area of the object, said signal light wave comprising at least one acousto-optic component frequency-shifted by said acoustic wave, (d) a light pump wave is generated, coherent with said incident wave at a frequency similar to the frequency of said acousto-optic component, (e) a complex index grating is formed in a dynamic holographic material by applying said signal wave and said pump wave to said material, and (f) a digital parameter relating to the light intensity in this three-dimensional area is obtained from said complex index grating.