Fig. 3: Phantom optoacoustic imaging.
From: Nonlinearity of optoacoustic signals and a new contrast mechanism for imaging
a and b Reconstructed image of absorption coefficient at light fluence 1.5 ± 0.02 and 9 ± 0.1 mJ/cm2, respectively, 200 kHz - 8 MHz band-pass filter. c Reconstructed image of thermally excited third-order nonlinear susceptibility \(({{\rm{\chi }}}_{{th}}^{(3)})\) by using the modified model-based algorithm, according to Eqs. (14) and (15). Ratio values show the ratio between the mean value of the reconstructed data at Ethanol and Water tubes
