Rai Mani Ratnam, Vijayakumar A, Rosen Joseph
Opt Lett. 2018 Mar 1;43(5):1043-1046. doi: 10.1364/OL.43.001043.
Interferenceless coded aperture correlation holography (I-COACH) is an incoherent digital holography technique developed to record and reconstruct 3D images of objects without two-wave interference. Herein, we introduce a novel technique to extend the field of view (FOV) of I-COACH beyond the limit imposed by the ratio between the finite area of the image sensor and the magnification of the optical system. Light diffracted from a point object located on the optical axis is modulated by a pseudorandom coded phase mask, and the central part of the point spread hologram (PSH) on the image sensor is recorded. The point object is shifted laterally to predetermined lateral locations in order to collect the exterior parts of the PSH. The recorded PSHs are stitched together to produce a synthetic PSH (SPSH) with an area nine times that of any individual PSH recorded by the image sensor. An object with a lateral extent beyond the FOV limit of the image sensor is placed at the same axial location as the point object, and the object hologram is recorded. The object is reconstructed by a cross-correlation between the zero-padded object hologram and the SPSH. Hence, the object parts beyond the FOV limit of the image sensor are recovered. An SPSH library is created for different axial planes, and the corresponding axial planes of the object are reconstructed.
无干涉编码孔径相关全息术（I-COACH）是一种非相干数字全息技术，旨在记录和重建物体的三维图像而无需双波干涉。在此，我们介绍一种新技术，以扩展I-COACH的视场（FOV），超越图像传感器有限面积与光学系统放大倍数之比所施加的限制。从位于光轴上的点物体衍射的光由伪随机编码相位掩模调制，并记录图像传感器上点扩散全息图（PSH）的中心部分。将点物体横向移动到预定的横向位置，以收集PSH的外部部分。将记录的PSH拼接在一起，以产生一个合成PSH（SPSH），其面积是图像传感器记录的任何单个PSH面积的九倍。将横向范围超出图像传感器FOV限制的物体放置在与点物体相同的轴向位置，并记录物体全息图。通过对零填充物体全息图和SPSH之间的互相关来重建物体。因此，可恢复图像传感器FOV限制之外的物体部分。为不同的轴向平面创建一个SPSH库，并重建物体的相应轴向平面。
