Acoustic reflector combined with optical detection for photoacoustic section imaging

The method proposed in this work combines the advantages of optical detection (optical and acoustical transparency) with 2D slice imaging, using an optical interferometer combined with an acoustic reflector. The concave reflector has the shape of an elliptical cylinder and concentrates the acoustic wave generated around one focal line in the other one, where an optical beam probes the temporal evolution of acoustic pressure. This yields line projections of the initial acoustic pressure sources at distances corresponding to the time of flight. Image reconstruction from the signals recorded while rotating the sample about an axis perpendicular to the optical detector requires only the application of the inverse Radon transform. The resolution and sensitivity of the detection system were investigated in experiments on phantom samples. Furthermore, the imaging system was tested on a real biological sample.