Abstract

We measured the photothermal lens signal in samples exhibiting high turbidity using a pump-probe scheme. We show that the photothermal lens signal properties remain nearly unchanged up to values of turbidity of 6 cm^?1 despite the signal reduction due to the decrease of excitation power associated to turbidity losses. The signal starts decreasing abruptly for values of turbidity larger than 6 cm^?1. Multiple light scattering yields a reduction of the temperature gradients, which results in a decrease of the effective signal. However, the signal-to-noise ratio remains above 50 for turbidity values of 9 cm^?1, which corresponds to a reduction of light transmission by more than four orders of magnitude. We report on the detection of the photothermal lens signal through a 2 mm layer of organic tissue with a signal-to-noise ratio of about 500. This technique appears promising for imaging applications in organic samples, which usually exhibit high turbidity for visible and near-infrared light.

Determination of linear and nonlinear absorption of metallic colloids using photothermal lens spectrometry

A. Marcano O., F. Delima, Y. Markushin, and N. Melikechi
J. Opt. Soc. Am. B 28(2) 281-287 (2011)

Measurement of the refractive index of highly turbid media

W. R. Calhoun, H. Maeta, A. Combs, L. M Bali, and S. Bali
Opt. Lett. 35(8) 1224-1226 (2010)

Measurement of the refractive index of highly turbid media: comment

K.- E. Peiponen, J. Räty, and I. Niskanen
Opt. Lett. 35(24) 4108-4108 (2010)

Theoretical, experimental, and computational aspects of optical property determination of turbid media by using frequency-domain laser infrared photothermal radiometry

Lena Nicolaides, Yan Chen, Andreas Mandelis, and I. Alex Vitkin
J. Opt. Soc. Am. A 18(10) 2548-2556 (2001)

Measurement of the refractive index of highly turbid media: reply to comment

W. Calhoun, H. Maeta, A. Combs, L. M. Bali, and S. Bali
Opt. Lett. 36(16) 3172-3172 (2011)