Fig. 1. Schematics of photon transport process in biological tissues with and without ultrasound modulation. (a) Photon transport process without ultrasound modulation ; (b) photon transport process with ultrasound modulation

Fig. 2. Schematic diagram of acousto-optic tomography principle

Fig. 3. Diagrams of tissue. (a) Two-dimensional model; (b) grid division

Fig. 4. Ultrasonic source waveform and acousto-optic signal received by detector. (a) Ultrasonic source waveform; (b) acousto-optic signal

Fig. 5. Acousto-optic signal peak-to-peak value versus incident intensity value for different samples in simulation

Fig. 6. Relative intensity and peak-to-peak value of acousto-optic signal versus scattering coefficient in simulation. (a) Relative intensity of acousto-optic signal; (b) peak-to-peak value of acousto-optic signal

Fig. 7. Comparison between measured scattering coefficient and real scattering coefficient under two measurement methods in simulation. (a) Based on relative intensity of acousto-optic signal; (b) based on peak-to-peak value of acousto-optic signal

Fig. 8. Schematic diagram of acousto-optic tomography experimental system

Fig. 9. Acousto-optic signal detected in experiment

Fig. 10. Acousto-optic signal peak-to-peak value versus incident intensity under different sample scattering coefficients in experiment

Fig. 11. Relative intensity and peak-to-peak value of acousto-optic signal versus scattering coefficient in experiment. (a) Relative intensity of acousto-optic signal; (b) peak-to-peak value of acousto-optic signal

Fig. 12. Comparison between measured value and real value of scattering coefficient under two measurement methods in experiment. (a) Based on relative intensity of acousto-optic signal; (b) based on peak-to-peak value of acousto-optic signal

Fig. 13. Measured results by relative intensity of acousto-optic signal after expanding range of sample scattering coefficient. (a) Relative intensity of acousto-optic signal versus scattering coefficient; (b) comparison between measured and actual scattering coefficients