Experiments with three-dimensional optical microscopy using axially distributed sensing

We present experiments on three-dimensional (3D) optical microscopy using inexpensive commercial cameras. Microscopic samples are magnified optically using a microscope objective and tube lens. When the resulting image is recorded, the number of pixels the magnified image occupies is limited by the low numerical aperture (NA) of the camera and the lack of a camera zoom lens. To increase the area of the image being captured by the camera, we use an additional lens to increase the NA of the intermediate image space. The resulting intermediate image is recorded by moving the camera along a common optical axis to record a set of 2D images. 3D volumetric images are computationally reconstructed from this set of 2D images using an algorithm based on ray back-projection.