Opt Lett. 2020 Feb 1;45(3):632-635. doi: 10.1364/OL.379844.
The laser illumination delivery method is important in designing probes that achieve high imaging quality and deep tissue penetration. Here we present a novel, to the best of our knowledge, fiber diffuser tip using microspheres dispersed within an ultraviolet adhesive to scatter light. This diffuser keeps the skin surface fluence under the maximum permissible exposure, while enabling higher laser energy injection to enhance the photoacoustic (PA) signal generated from the tissue. We compare the light diffusion effects of different microsphere materials, sizes, and concentrations, and find that 10 µm silica microspheres provide the best light scattering with minimal 5% output energy loss. With the Zemax simulation and experimental validation, we show that this fiber diffuser tip is a valuable tool for endo-cavity PA imaging.
激光照明传输方法在设计能够实现高成像质量和深组织穿透的探头时非常重要。在这里，我们提出了一种新颖的光纤扩散器尖端，该尖端使用分散在紫外光胶中的微球来散射光。这种扩散器可以在保持皮肤表面辐照度低于最大允许暴露量的情况下，允许更高的激光能量注入，从而增强组织产生的光声（PA）信号。我们比较了不同微球材料、尺寸和浓度的光扩散效果，发现 10 µm 二氧化硅微球提供了最佳的光散射效果，同时能量损失最小，仅为 5%。通过 Zemax 模拟和实验验证，我们表明这种光纤扩散器尖端是内腔 PA 成像的一种有价值的工具。
