Frequency domain photothermoacoustic signal amplitude dependence on the optical properties of water: turbid polyvinyl chloride-plastisol system.
Photoacoustic (more precisely, photothermoacoustic) signals generated by the absorption of photons can be related to the incident laser fluence rate. The dependence of frequency domain photoacoustic (FD-PA) signals on the optical absorption coefficient (micro(a)) and the effective attenuation coefficient (micro(eff)) of a turbid medium [polyvinyl chloride-plastisol (PVCP)] with tissuelike optical properties was measured, and empirical relationships between these optical properties and the photoacoustic (PA) signal amplitude and the laser fluence rate were derived for the water (PVCP system with and without optical scatterers). The measured relationships between these sample optical properties and the PA signal amplitude were found to be linear, consistent with FD-PA theory: micro(a)=a(A/Phi)-b and micro(eff)=c(A/Phi)+d, where Phi is the laser fluence, A is the FD-PA amplitude, and a, ...,d are empirical coefficients determined from the experiment using linear frequency-swept modulation and a lock-in heterodyne detection technique. This quantitative technique can easily be used to measure the optical properties of general turbid media using FD-PAs.
Spirou
Gloria M
GM
Department of Medical Physics, McMaster University, Hamilton, ON, Canada. gloria.spirou@gmail.com
Mandelis
Andreas
A
Vitkin
I Alex
IA
Whelan
William M
WM
D000162:Acoustics; D004867:Equipment Design; D008027:Light; D015233:Models, Statistical; D008962:Models, Theoretical; D009391:Nephelometry and Turbidimetry; D055095:Optics and Photonics; D017785:Photons; D011143:Polyvinyl Chloride / Q000737:chemistry*; D012542:Scattering, Radiation; D012984:Software; D013696:Temperature; D014867:Water / Q000737:chemistry*
D014867:Water; D011143:Polyvinyl Chloride