数字全息技术在散射介质成像中的应用研究

Imaging through scattering media has been widely used in a variety of fields such as space remote-sensing, deep ocean exploration, biomedical diagnosis. However, most of the present techniques apply coherent light for illumination and phase control devices such as spatial light modulator（SLM）for phase compensation of the distorted wavefront, which greatly limit the imaging quality and speed. By combining digital holography and the memory effect of scattering media, the proposed method is capable of measuring the distorted wavefront of a single point source through scattering media. Consequently, the compensated phase required in the reconstruction is obtained. Then, the refocused scattered light, as well as higher imaging speed and better imaging quality through scattering media can be achieved. To improve the imaging quality, low coherence light source will be employed. Furthermore, image stitching and data integration method will be introduced to expand the field of view. The proposed project is expected to have better performance in both image quality and time resolution without using wavefront control devices, which relaxes the hardware requirements for experimental setup. This project will provide a new way for improving the efficiency, quality and field of view of imaging of objects behind the scattering medium.

光通过散射介质的成像技术在空间遥感、深海探测、生物医学诊断等领域有着广泛的应用。现有的散射成像技术大多需要相干光照明并借助空间光调制器等相位调控器件补偿畸变的波前相位，限制了成像质量和速度。本项目将数字全息技术和散射介质的记忆效应相结合，通过精确测量点光源经过散射介质后的波前畸变，得到再现过程中需要的补偿相位。在补偿相位的作用下，散射光可以重新聚焦，借助散射介质的记忆效应，可实现散射介质后物体的快速、高质量成像。为了降低散斑噪声对成像质量的影响，拟采用低相干光照明，提高成像质量。通过视场拼接和数据融合技术，扩大成像视场。本研究方法无需使用波前调控器件，降低对系统硬件的要求，且具有较高的成像质量和时间分辨率。通过本项目研究，希望为散射介质后物体的成像提供一种新的思路和手段。

光通过散射介质的成像技术在空间遥感、深海探测、生物医学诊断等领域有着广泛的应用。本项目将数字全息技术和散射介质的记忆效应相结合，实现了物体经过散射介质后的快速、高质量成像。提出了一种相间分区域校正遗传算法，有效提升了散射光场聚焦效率和聚焦效果，利用该算法对散射光场的水平和竖直两个正交偏振分量校正，实现了任意偏振态照明光下散射介质后物体的成像；将相间分区域校正方法和光学微操纵技术结合，实现了对散射介质后微粒的捕获和二维操纵；提出了一种基于叠层衍射技术和浴帘效应相结合的散射介质后成像方法，突破了记忆效应限制，实现了散射介质后非稀疏性样品高质量成像；研究了基于压缩感的传输矩阵测量法，实现了散射介质后对相位型物体的定量测量及动态成像。. 项目执行期间，在Optics Express, Applied Optics, Optics Letters, Journal of Optics等期刊共发表SCI收录学术论文12篇。参加2次国际学术会议和2次国内学术会议。培养博士毕业生2名，1名博士研究生获国家项目资助美国普渡大学进行交流培养。