Three-dimensional light field microscope based on a lenslet array

Most conventional microscopes can only acquire two-dimensional (2D) images. However, there is increasing demand for microscopes capable of acquiring three-dimensional (3D) images for use in biological research. To improve observations of in vivo specimens, we develop a novel one snap-shot 3D light field microscope with high spatial resolution. By adding a lenslet array and focusing optics into the optical train of a conventional microscope, we are able to simultaneously capture seven sub-aperture images from different perspectives in a single shot, and finish 3D surface reconstruction of the specimen. In this paper, we present a functioning prototype of a novel 3D light field microscope using different objectives, and describe its design and image quality. During 3D image reconstruction, we use an optical flow method and back-projection interpolation to improve the resolution of the subimages. The performance of the novel light field microscope is analyzed theoretically and experimentally. Multiple perspective images are obtained using an objective with 20 × /NA 0.4. These images are 1050 × 1050 pixels with a depth of view of 200 μm. For our microscope, the highest resolvable group of USAF 1951 target is about group 7.5. 3D reconstructions of various specimens are successfully created using these images. This novel microscopy system is suitable for various applications in 3D imaging and optical metrology.