Theoretical analysis for conversion efficiency of laser generation of acoustic waves in liquid

Abstract

In order to implement laser generation of acoustic waves in liquid efficiently, the optical-acoustic conversion efficiency was calculated and its influenced factors were analyzed, such as, time-domain power distribution, peak power density and pulse width of laser, and optical absorption coefficient of fluid medium. The theoretical analysis shows that: the larger the peak power density is, the larger the conversion efficiency will be; The growth rate of conversion efficiency of Gaussian pulse laser generation of acoustic waves is the largest; With the increasing of optical absorption coefficient or pulse width, the optical-acoustic conversion efficiency can reach a maximum value; Under the same conditions, comparing with triangle and Gaussian laser pulse, the optical-acoustic conversion efficiency is the largest when the power distribution of pulse laser is sinusoid function waveform.