Figure 4
(a,b) The ultrasound transducer measurements in transmission-mode are shown with the corresponding detection times of the photoacoustic and laser induced ultrasound signal. (b) For the marked surface, the laser induced ultrasound signal is stronger than the photoacoustic signal. (c) Detection times using speckle sensing and its standard deviation for the photacoustic signal and for the laser induced ultrasound signal at the phantom surface. The state of the art measurement using the ultrasound transducer matches the time interval for speckle sensing.
