Engineered Point Spread Function for Simultaneous Extended Depth of Field and 3D Ranging

摘要

Optical systems utilize waveplates to simultaneously encode information for increasing image depth of field and for providing a depth map of the imaged object or sample. These waveplates are configured to result in a focus-invariant point spread function in one focal region, and to result in point spread functions that vary as a function of range within the imaged object in a different focal region. For example, a basic compound microscope might have a specially shaped waveplate inserted at the back aperture plane of the microscope objective to manipulate the phase of the wavefront. An image formed on one side of the plane of best focus is focus invariant, and is brought into focus by a restoring algorithm. An image formed on the other side of the plane of best focus captures point spread functions comprising rings that vary with depth within the imaged object.

主权项

1. The method of imaging a three-dimensional (3D) object that simultaneously accomplishes extended depth of field and 3D ranging, the method comprising the steps of:
(a) providing an optical system including a waveplate, the waveplate constructed and arranged to modify the optical path of light from a 3D object such that optical system simultaneously produces an extended depth of field (EDF) image of the object and produces a depth-encoded image of the object having a point spread function (PSF) which varies according to range; (b) passing light from the 3D object through the optical system; (c) detecting the EDF image with a first detector and detecting the depth-encoded image with a second detector, the second detector spaced apart from the first detector; (d) digitally filtering the detected EDF image; and (e) producing a depth map from the detected encoded image.