摘要
声学分辨率光声显微镜探测深度可达厘米量级,已有声学分辨率光声显微镜照明方式的主流设计方案在明场、暗场照明方式切换,光能利用率等方面仍存在不足,在一定程度上限制了声学分辨率光声显微镜系统的应用范围。提出了一种能够提高光能利用率,可实现明场、暗场照明切换并增大调节范围的声学分辨率光声显微镜系统设计,利用凸透镜对光束的会聚功能,对发散环形光束产生一定程度的聚焦,减小环形光束的环带尺寸。蒙特卡罗模拟结果显示,最终入射在组织表面的光斑直径得到有效减小,组织中超声换能器有效探测区域的光能流量分布最多可增强6倍,因此光声信号强度也相应地得到线性增强;与此同时,凸透镜的加入还增加了系统光聚焦深度的调节范围,在超声换能器聚焦深度不变的情况下,调节系统的光聚焦深度,有助于在不同样品中获得最佳的光声信号强度。
Imaging depth of acoustic resolution photoacoustic microscopy is capable of reaching the centimeter level. There are several drawbacks regarding to the mainstream illumination designs of current acoustic resolution photoacoustic microscopy systems, e.g. switch between bright field illumination and dark field illumination is not available, and the utilization efficiency of laser energy is very low. Therefore, the application of the system is limited. A novel optical illumination design has been proposed to overcome these limitations. A convex lens is applied to focus the diverging ring-shape light before it is reflected by the optical condenser, as a result, the ultimate laser spot on the sample surface can be smaller. The Monte Carlo simulation results show that laser fluence within the volume of effective ultrasound detection has been improved by as much as 6 times, and therefore the intensity of photoacoustic signals can be linearly increased as well. On the other hand, the tuning range of optical focus depth of the system has also been expanded, and after specific tuning, optimal photoacoustic signals can be obtained within different kinds of samples.
出处
《中国激光》
EI
CAS
CSCD
北大核心
2016年第2期116-123,共8页
Chinese Journal of Lasers
基金
国家自然科学基金(81427804
61405234
81430038)
深圳市科创委基础研究项目(JCYJ20140416122811974)
关键词
医用光学
光声显微成像
蒙特卡罗模拟
声学分辨率
medical optics
photoacoustic microscopy imaging
Monte Carlo simulation
acoustic resolution
