Comparison of time domain and frequency domain of multi-wavelength photoacoustic signals

In order to analysis the characteristics and differences of photoacoustic imaging signal under different wavelengths in time domain and frequency domain, multi-wavelength photoacoustic imaging experiment with different targets including graphite phantom, pork and pig blood phantom was designed. The results show that the performance of different targets was quite different in time domain and frequency domain. The acoustic spectrum of photoacoustic signals for different targets was unique. Frequencies corresponded to the peaks of acoustic spectrum were same. The performance can be utilized for tissue characterization description and component identification. The research is helpful for organizational recognization by using photoacoustic imaging. And it will be the fundamental research for further frequency-domain analysis and study of multispectral photoacoustic imaging.