Abstract: A sensing device with an odd-symmetry grating projects near-field spatial modulations onto a closely spaced photodetector array. The grating includes upper and lower features that define boundaries of odd symmetry. The features include upper and lower segments of various widths on opposite sides of each boundary, the upper segments at a height sufficient to induce one half wavelength of retardation in the band of interest relative to the lower segments. The resultant interference produces the spatial modulations for capture by the array. Photographs and other image information can be extracted from the captured data.

Abstract: A sensing device with an odd-symmetry grating projects near-field spatial modulations onto a closely spaced photodetector array. Due to physical properties of the grating, the spatial modulations are in focus for a range of wavelengths and spacings. The spatial modulations are captured by the array, and photographs and other image information can be extracted from the resultant data. Used in conjunction with a converging optical element, versions of these gratings provide depth information about objects in an imaged scene. This depth information can be computationally extracted to obtain a depth map of the scene.

Abstract: Image-sensing devices include odd-symmetry gratings that cast interference patterns over a photodetector array. Grating features offer considerable insensitivity to the wavelength of incident light, and also to the manufactured distance between the grating and the photodetector array. Photographs and other image information can be extracted from interference patterns captured by the photodetector array. Images can be captured without a lens, and cameras can be made smaller than those that are reliant on lenses and ray-optical focusing.

Abstract: A sensing device with an odd-symmetry grating projects near-field spatial modulations onto a closely spaced photodetector array. The grating includes upper and lower features that define boundaries of odd symmetry. The features include upper and lower segments of various widths on opposite sides of each boundary, the upper segments at a height sufficient to induce one half wavelength of retardation in the band of interest relative to the lower segments. The resultant interference produces the spatial modulations for capture by the array. Photographs and other image information can be extracted from the captured data.

Abstract: A sensing device projects near-field spatial modulations onto a closely spaced photodetector array. Due to physical properties of the grating, the point-spread response distributes spatial modulations over a relatively large area on the array. The spatial modulations are captured by the array, and photographs and other image information can be extracted from the resultant data. An image-change detector incorporating such a sensing device uses very little power because only a small number of active pixels are required to cover a visual field.

Abstract: A sensing device with an odd-symmetry grating projects near-field spatial modulations onto a closely spaced photodetector array. Due to physical properties of the grating, the spatial modulations are in focus for a range of wavelengths and spacings. The spatial modulations are captured by the array, and photographs and other image information can be extracted from the resultant data. Used in conjunction with a converging optical element, versions of these gratings provide depth information about objects in an imaged scene. This depth information can be computationally extracted to obtain a depth map of the scene.

Abstract: Described are imaging devices that employ patchworks of diffractive structures as focusing optics. Each diffractive structure best focuses light over a relatively narrow cone of incident angles, and provides suboptimal focusing for incident angles outside that cone. Different diffractive structures best focus different angular ranges, with the patchwork thus providing an overall focusable response for the relatively broad range of angles required to image a scene. Images can be captured without a lens, and cameras can be made smaller than those that are reliant on lenses and ray-optical focusing.

Abstract: A Compressed Sensing (CS) based image reconstruction method and system is described herein which may be used to reduce the X-ray dose radiation in Computed Tomography (CT) or to decrease the scan duration in MR imaging (MRI). Methods and systems described herein may address problems that have hindered the clinical usage of CS, i.e. computation complexity and modeling problems. Using the described algorithm, high quality images may be recovered from undersampled data which may help to reduce the scan time and the exposed invasive radiations. Using the same set of data in conventional image reconstruction algorithms (e.g. Filtered Back Projection (FBP) in CT) may cause severe streak artifacts and may take significantly more time using Graphics Processing Units (GPU) and parallel clusters with the conventional CS-based methods. This method can be used other imaging modalities using Radon transform (such as C-Arm and electron tomography, for example).

Abstract: An array of diffraction-pattern generators employ phase anti-symmetric gratings to projects near-field spatial modulations onto a closely spaced array of photoelements. Each generator in the array of generators produces point-spread functions with spatial frequencies and orientations of interest. The generators are arranged in an irregular mosaic with little or no short-range repetition. Diverse generators are shaped and placed with some irregularity to reduce or eliminate spatially periodic replication of ambiguities to facilitate imaging of nearby scenes.

Abstract: A sensing device with an odd-symmetry grating projects near-field spatial modulations onto a closely spaced photodetector array. Due to physical properties of the grating, the spatial modulations are in focus for a range of wavelengths and spacings. The spatial modulations are captured by the array, and photographs and other image information can be extracted from the resultant data. Used in conjunction with a converging optical element, versions of these gratings provide depth information about objects in an imaged scene. This depth information can be computationally extracted to obtain a depth map of the scene.