采用短相干光数字全息术实现反射型微小物体的三维形貌测量

针对反射型微小物体，设计了一种可在三维形貌测量中实现微小物体分层记录的短相干光源无透镜傅里叶变换数字全息记录系统，并利用该系统对锥形微孔壁实现了分层记录.该系统可通过调节待测物体的位置，改变全息记录中的物光光程，从而获得重构三维物体所需要的一系列子全息图.该系统具有光路简洁，系统的附加误差小的特点.实验测量的轴向误差约为3.5%，横向误差约为2.6%.此外，在三维重构的过程中，为避免因散斑噪声较大而无法利用位相信息进行三维重构的情况，采用了最小二乘多项式拟合方法，将微小物体的一系列再现强度图像进行三维重构.由于避免了复杂的相位展开，所以不但运算简单，而且具有较强的抗散斑噪声能力.

Three-dimensional surface contouring of reflecting micro-object by digital holography with short-coherence light source

In this paper, a new lensless digital holography system with short-coherent light source is designed for recording three-dimensional surface contour of reflecting micro-object. In the experiment, the different layers on the inner wall of a conical pore are recorded by changing the path length of object beams to record a series of sub-holograms for three-dimensional reconstruction. This makes the recording system compact and reduces the additional error in the recording. The measured longitudinal error is about 3.5%,with a lateral error of about 2.6%. Besides, the least squares polynomial fit method is used for the first time to carry out three-dimensional reconstruction with a series of two dimensional intensity images of a micro-object, which not only reduces obviously the complication of the three-dimensional reconstruction, but also can be used to carry out three-dimensional reconstruction of a micro-object with strong laser speckle noise, of which the phase images can not be obtained from the phase-unwrapping process.