论文标题
无透镜内全息显微镜，具有低时空相干性的光源
Lensless in-line holographic microscopy with light source of low spatio-temporal coherence
论文作者
论文摘要
具有连贯或部分相干光源的无透镜显微镜是一种众所周知的成像技术，通常称为数字在线全息显微镜。在既定的方法中，光的空间和时间连贯性在确定重建对象的分辨率方面起着至关重要的作用。我们报告了无透镜显微镜，其空间扩展的白色LED是低空间和非常低的时间连贯性的光源。可以使用卷积操作获得两个平行平面之间的波场传播，其中卷积内核取决于对象传感器距离和光源的特性。对于未知特征的光源，该内核是未知的函数。在提出的重建方法中，我们将非常大的卷积内核（128 x 128）分解为一个小的未知光源特异性内核（9 x 9尺寸）和已知的无光源核心（尺寸128 x 128）。这大大减少了在系统识别步骤中要估计的参数数量，在此处通过一次成像对已知的显微对象进行了成像。最终未知的对象估计已使用上限约束反卷积进行。已经证明了〜1-2千分尺的横向分辨率。
Lensless microscopy with coherent or partially coherent light sources is a well known imaging technique, commonly referred as digital in-line holographic microscopy. In the established methods, both the spatial and temporal coherence of light play a crucial role in determining the resolution of reconstructed object. We report lensless microscopy with a spatially extended white LED, a light source of low spatial and very low temporal coherence. The wave-field propagation between two parallel planes can be obtained using a convolution operation, where the convolution kernel depends on the object-sensor distance and the characteristics of the light source. For a light source of unknown characteristics, this kernel is an unknown function. In the proposed reconstruction method, we decompose an unknown convolution kernel of very large size (128 X 128) into a small unknown light-source-specific kernel (size 9 X 9) and a known light-source-independent kernel (size 128 X 128). This drastically reduces the number of parameters to be estimated at the system identification step, which has been performed here by one time imaging of the known microscopic objects. Final unknown object estimation has been performed using the upper-bound constrained deconvolution. A lateral resolution of ~1-2 micrometer has been demonstrated.
