Figure 6From: Nanostructured copper/porous silicon hybrid systems as efficient sound-emitting devicesRatio of photo-acoustic responses P c / P sio2 (black squares) and P psi / P sio2 (green circles) as a function of laser modulation frequency. Pc, Psio2, and Ppsi represent the photo-acoustic response of the local plasmon resonator with and without a porous column layer and that of nanoPS + Cu, respectively. The red and blue dashed lines show the calculation result for Pc/Psio2 and Ppsi/Psio2, respectively.Back to article page