Effect of scattering on nonlinear optical scanning microscopy imaging of highly scattering media

The intensity of two-photon excited fluorescence (TPF) generated by ultrash ort laser pulses was measured as a function of the depth of a focal point i nside highly scattering media. The purpose was to investigate the spatial l ocation of TPF in a scattering medium. Owing to the scattering, the intensi ty of the incident beam as well as the generated TPF signal wets attenuated exponentially as the focal point was scanned into the medium. As the scatt ering strength of the medium was increased, the TPF was not confined to the focal region and had a wider distribution. These observations show that th e scattering will result in the degradation of the ability of optical depth sectioning of nonlinear optical scanning microscopy. (C) 2000 Optical Soci ety of America.