Optical Sectioning Microscopy by Wavelength Scanning Digital Interference Holography

该奖项将开发一种简单而新颖的多功能数字全息显微镜设备，用于成像三维微观体积物体。从该装置得到的图像在横向和纵向都具有亚微米分辨率。此外，完全抑制了由于离焦物平面引起的图像模糊和退化。该装置是基于数字重建和干涉的数字记录的全息图像的数量，而波长的照明激光扫描。由于全息图保留了光场的所有振幅和相位信息，并且由于全息图的数字操作自由，因此可以在数字虚拟空间中进行物理空间中完全不可能的干涉过程。当许多不同波长的全息重建光场叠加时，如果波长是规则间隔的，那么干涉它们导致光强度只集中在物体点上-光通过空间的传播实际上被消除了。当聚焦时，数字上，在一个图像平面上，只有那些点对应于任何不连续或不规则性，如细胞表面和结构的对象呈现明亮的图像斑点。这种效果类似于扫描共焦显微镜图像，但这种系统具有显著的潜在优势。它没有机械运动部件，图像采集由N次曝光的二维图像组成，而不是逐像素构建的3D体积。通过适当选择波长间隔，可以很容易地控制物体的物理尺寸和分辨率范围。由于全息相位信息是现成的，进一步的干涉或全息图像处理是可能的。此外，获奖系统的光学切片图像可以重新组装成三维数字模型，该模型可以进一步用于特定应用，例如校正比例失真，任意截面和剖视图，以及自动特征增强和识别。该系统提供了一种简单易行的获取和操作显微物体三维数字模型的模式，具有潜在的影响显微光学成像的一般领域。

This award will develop a simple yet novel and versatile digital holographic microscopedevice for imaging three-dimensional microscopic volume objects. The resultant imagesobtained from this device will have submicron resolution in both the lateral andlongitudinal directions. Moreover, the blurring and degrading of images due to out-of-focus object planes are completely suppressed. The device is based on numericalreconstruction and interference of a number of digitally recorded holographic images,while the wavelength of the illuminating laser is scanned. Because a hologram retainsall of the amplitude and phase information of the light field and because of the freedomof digital manipulation of the holograms, it is possible to carry out an interferenceprocess in the numerical virtual space that is quite impossible in physical space. Whena number of holographically recreated light fields of varying wavelengths aresuperposed, and if the wavelengths are regularly spaced, then the interference amongthem result in the light intensity being concentrated at object points only - propagationof light through space is in effect eliminated. When focused, numerically, on animage plane, only those points corresponding to any discontinuities or irregularities,such as cellular surfaces and structures, of the object render bright image spots. Theresulting effect is analogous to scanning confocal microscope images, but thissystem presents significant potential advantages. It has no mechanical moving parts.The image acquisition consists of N exposures of two dimensional images, instead ofpixel-by-pixel build-up of 3D volume. The range of physical sizes and resolution ofobjects that can be imaged is readily controlled by proper choice of the wavelengthintervals. And with the holographic phase information readily available, furtherinterferometric or holographic image processing is possible. Furthermore, the opticalsectioned images of the awarded system can be reassembled into a three-dimensionaldigital model that can be further manipulated for specific applications, such ascorrection of scale distortion, arbitrary section and cut-away views, and automaticfeature enhancement and identification. This system has a potential to impactthe general field of microscopic optical imaging by providing a simple and versatilemode of acquiring and manipulating three-dimensional digital model of microscopicobjects.