Selective acoustic phonon mode excitation of multi-mode silver nanoprisms

► Photo-induced acoustic phonons of the nanoprisms, which are breathing mode and totally symmetric mode, have been studied. ► We used two properly timed pump pulses to directly excite totally symmetric mode of the nanoprisms. ► Since the totally symmetric mode is mainly caused by impulsive electron stress, one could study electron dynamics from coherent acoustic phonon. We studied the relationship between excitation power and vibration amplitude, and the totally symmetric mode would disappear when excitation power is beyond a certain value.