Focusing light within scattering media for photoacoustic tomography in a limited-view-angle tomography setting

In photoacoustic there is a trade-off between resolution and contrast at each depth, so it is difficult to accurately depict objects in deep regions. In recent years, scattering light control has been studied in various imaging fields. In this report, this control was applied to photoacoustic signals to increase the signal amplitude in the scatting media. To control the light, we used a feedback optical wavefront shaping technique and genetic algorithms (GAs) to optimize feedback. For the feedback signal, we use a photoacoustic signal in a transducer setting and a photoacoustic image in a limited-view-angle linear array probe setting. We demonstrated that wavefront light optimized by changing the light's speckle size can enhance the photoacoustic signal in tissue-mimicking phantoms in a confirmation experiment. We need to improve speed for biological imaging, but focusing light through scattering materials has potential in various biomedical applications.