Fig. 4

Photoacoustic signal comparison for an uncoated nanosphere (\(a=30\) nm). a Ten-nanosecond-wide Gaussian laser pulse. b Two-nanosecond-wide Gaussian laser pulse. The nanosphere is placed in water and three different values of \({G}_{12}=200\,{\mathrm{{{MW}}}}\,{\mathrm{{{m}}}}^{-2}\,{\mathrm{{{K}}}}^{-1}\), \({G}_{12}=20\,{\mathrm{{{MW}}}}\,{\mathrm{{{m}}}}^{-2}\,{\mathrm{{{K}}}}^{-1}\), \({G}_{12}=2\,{\mathrm{{{MW}}}}\,{\mathrm{{{m}}}}^{-2}\,{\mathrm{{{K}}}}^{-1}\). Higher sensitivity of the generated photoacoustic signal with the interfacial resistance for the sharper laser pulse is evident