Photorefractive detection of tagged photons in ultrasound modulated optical tomography of thick biological tissues.
We present a new and simple method to obtain ultrasound modulated optical tomography images in thick biological tissues with the use of a photorefractive crystal. The technique offers the advantage of spatially adapting the output speckle wavefront by analysing the signal diffracted by the interference pattern between this output field and a reference beam, recorded inside the photorefractive crystal. Averaging out due to random phases of the speckle grains vanishes, and we can use a fast single photodetector to measure the ultrasound modulated optical contrast. This technique offers a promising way to make direct measurements within the decorrelation time scale of living tissues.
Ramaz
F
F
Forget
B
B
Atlan
M
M
Boccara
A C
AC
Gross
M
M
Delaye
P
P
Roosen
G
G