Balu Mihaela, Baldacchini Tommaso, Carter John, Krasieva Tatiana B, Zadoyan Ruben, Tromberg Bruce J
University of California, Irvine, Beckman Laser Institute Laser Microbeam and Medical Program, Irvine, CA 92617, USA.
J Biomed Opt. 2009 Jan-Feb;14(1):010508. doi: 10.1117/1.3081544.
We present a comparative study of two-photon excited fluorescence (TPEF) and second harmonic generation (SHG) imaging in turbid media at 800- and 1300-nm excitation. The depth-dependent decay of TPEF and SHG signals in turbid tissue phantoms is used to estimate the impact of light scattering on excitation intensity at each wavelength. A 50 to 80% increase in scattering length is observed using 1300-nm excitation, while peak TPEF emission intensity is obtained 10 to 20 microm beneath the surface for both sources. The increased penetration depth at 1300 nm is confirmed by TPEF and SHG microscopy of tissue phantoms composed of gelatin/microspheres and 3-D organotypic collagen-fibroblast cultures, respectively. Our results establish the feasibility of 1.3-microm excitation in nonlinear optical microscopy.
我们展示了在800纳米和1300纳米激发下，对浑浊介质中的双光子激发荧光（TPEF）和二次谐波产生（SHG）成像的比较研究。浑浊组织模型中TPEF和SHG信号随深度的衰减用于估计光散射对每个波长激发强度的影响。使用1300纳米激发时，观察到散射长度增加了50%至80%，而两种光源在表面下方10至20微米处均获得了TPEF发射峰值强度。分别由明胶/微球和三维器官型胶原-成纤维细胞培养物组成的组织模型的TPEF和SHG显微镜检查证实了1300纳米处穿透深度的增加。我们的结果确立了非线性光学显微镜中1.3微米激发的可行性。
