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<sup>?1</sup> 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<sup>?1</sup>. 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<sup>?1</sup>, 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.

PDF Article

Cited By

You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
Login to access OSA Member Subscription