Eur. Phys. J. Special Topics 153, 491-495 (2008)
https://doi.org/10.1140/epjst/e2008-00492-6

A calibration technique for frequency domain photothermoacoustics^*

¹ Department of Medical Physics, McMaster University, Hamilton, Ontario, Canada
² Center of Advanced Diffusion-Wave Technologies, Departments of Mechanical and Industrial Engineering, University of Toronto, Toronto, Ontario, Canada
³ Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
⁴ Ontario Cancer Institute/Princess Margaret Hospital/University Health Network, Division of Biophysics and Bioimaging, University of Toronto, Toronto, Ontario, Canada
⁵ Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada
⁶ Department of Physics, Ryerson University, Toronto, Ontario, Canada

Abstract

Photoacoustic (or more precisely, photothermoacoustic) signals are generated by the absorption of photons, expressed as acoustic waves, and can be related to the incident laser fluence rate. Here a calibration procedure for frequency domain (FD) photoacoustics is presented which utilizes the relationship between photoacoustic (PA) signal amplitude and laser fluence rate. The sample is irradiated with a continuous wave laser which is amplitude modulated at varying frequencies. Applying the calibration procedure to the PA detected signals, a linear relationship is obtained between the fluence rate and the signal amplitude.