Lin W C, Motamedi M, Welch A J
Appl Opt. 1995 Dec 1;34(34):7979-85. doi: 10.1364/AO.34.007979.
A pump (cw Ho-YAG laser) and probe (He-Ne laser) system was used to study the dynamics of the optical behavior of ocular tissue during laser heating. The nonlinear optical behavior of porcine corneal and vitreous-humor tissue was characterized in vitro by means of measurements of the radial profile of a He-Ne laser beam transmitted through the tissue. Temperature gradients in the tissue created by the absorption of pump radiation caused the probe beam to diverge. For constant laser power, the rate of divergence was made dependent on the spot size of the pump beam. The profile of the transmitted probe beam returned to its original magnitude and shape after the tissue was permitted to cool. This reversible change in optical behavior was attributed to the formation of a negative lens owing to thermally induced local gradients in the refractive index of the tissue.
使用泵浦（连续波 Ho-YAG 激光）和探测（氦氖激光）系统来研究激光加热过程中眼部组织光学行为的动力学。通过测量透过组织的氦氖激光束的径向分布，在体外对猪角膜和玻璃体组织的非线性光学行为进行了表征。泵浦辐射吸收在组织中产生的温度梯度导致探测光束发散。对于恒定的激光功率，发散速率取决于泵浦光束的光斑尺寸。在组织冷却后，透射探测光束的分布恢复到其原始大小和形状。这种光学行为的可逆变化归因于由于组织折射率的热诱导局部梯度而形成的负透镜。
