Noemí I. R. Rivera

Pseudoscopic imaging in a double diffraction process with a slit

Pseudoscopic images that keep a continuous parallax are shown to be possible due to a double diffraction process intermediated by a slit. One diffraction grating acts as a wavelength encoder of views while a second diffraction grating decodes the projected image. The process results in the enlargement of the image under common white light illumination.

Holo-television system with a single plane

We show a system capable of projecting a video scene onto a white-light holographic screen to obtain a kind of image that results in a plane in front of the screen. This holographic screen is mainly a diffractive lens and is constructed by holography. The image plane can be located at any azimuth angle and seen with continuous parallax and without the use of goggles or any special visualization equipment. The image is not volumetric, but when the plane is oblique to the observer its appearance looks very close to a real volumetric image.

Imaging with two spiral diffracting elements intermediated by a pinhole.

A pseudoscopic (inverted depth) image made with spiral diffracting elements intermediated by a pinhole is explained by its symmetry properties. The whole process is made under common white light illumination and allows the projection of images. The analysis of this projection demonstrates that the images of two objects pointing away longitudinally have the main features of standard pseudoscopic image points. An orthoscopic (normal depth) image has also been obtained with the breaking of the symmetry conditions.

3D imaging with a linear light source

In a previous system we showed how the three‐dimensionality of an object can be projected and preserved on a diffractive screen, which is just a simple diffractive holographic lens. A transmission object is illuminated with an extended filament of a white light lamp and no additional element is necessary. The system forms three‐dimensional (3D) images with normal depth (orthoscopic) of the shadow type. The continuous parallax, perfect sharpness and additional characteristics of the image depend on the width and extension of the luminous filament and the properties of the diffractive lens. This new imaging system is shown to inspire an interesting extension to non‐perfect reflective or refractive imaging elements because the sharpness of the image depends only on the width of the source. As new light sources are being developed that may result in very thin linear white light sources, for example, light emitting diodes, it may be useful to further develop this technique. We describe an imaging process in wh...

DIDACTICAL HOLOGRAPHIC EXHIBIT INCLUDING Holo TV (HOLOGRAPHIC TELEVISION)

Our Institute of Physics exposes since 1980 didactical exhibitions of holography in Brazil where nice holograms are shown altogether with basic experiments of geometric and wave optics. This experiments lead to the understanding of the phenomenon of images of an ample way. Thousands of people have been present at them, in their majority of the Universidade Estadual de Campinas, where since 2002 they have taken the format of a course without formal evaluation. This way the exhibition has been divided in four modules, in each one of them are shown different holograms, experiments of optics and applications of diffractive images with white light developed in the Institute of Physics. The sequence of the learning through the modules begins with the geometric optics, later we explain the wave optics and finally holography. The phenomenon of the diffraction in daily elements is shown experimentally from the beginning. As well as the application of the holographic screens in white light: the television images th...

Holoprojection of Transmission Objects Using a Diffractive Grating

A transmission object is projected on a diffractive grating. An extended filament of a white light lamp is the only additional element necessary to form images with normal depth.