Fig. 1.

Geometry of in silico simulation. (a) and (b) are the schematic diagrams of the simulation without the light catcher. (c) and (d) are for the case with the light catcher. The source light and its propagation models are composed of the water, skin, muscle, designed light catcher, and laser source. The origin of the coordinates is at the center of the water-skin interface. The laser source is placed 48 mm away from the target above the water-skin interface with an incidence angle of 30˚, surrounded by the concave-shape light catcher, of which the inner surface acts like a totally reflecting mirror. The dashed rectangle in (b) and (d) represents the ultrasound transducer.