蒙特卡罗模拟多束光辐照下生物组织中的光吸收分布

Monte Carlo Simulation of Light Absorption Distribution in Biological Tissue for Multi-beam Light

用蒙特卡罗方法模拟了均匀分布光和高斯分布光在生物组织内的传播。通过比较单束以及多束均匀分布光和高斯分布光照射下组织内的光子能量分布规律,分析了不同光源和光斑大小对光吸收分布的影响。结果表明:与均匀光束比较,高斯光束辐照时,激光能量较为集中,但侧向传播范围较窄。在总功率相同的情况下,使用单束大功率宽光源与多束功率较小的小光斑光源均能明显地增大光的侧向传播距离,但使用多束功率较小的小光斑光辐照时生物组织中的最大光吸收率增大。多束组合光源光束间距对光吸收分布影响很大。

Propagation of flat and Gaussian light beam in biological tissue is simulated with Monte-Carlo method. Through comparing the distribution of energy in biological tissue generated by single and multi-beam as well as flat and Gaussian light, influence of various light sources and the light spot size on the distribution of light absorption is analyzed. The results show that the laser energy is relatively concentrated while using Gaussian beam, but the lateral transport area is limited. Under the condition of the same total power, both large single beam and small multi-beam can enlarge the lateral area of the light propagation effectively, but the maximal light absorption rate increases for latter approach. For multi-beam combined sources, the distribution of light absorption is influenced by the distance between beams obviously.