In this series of digital art holograms and lenticulars, we used the HoloCam Portable Light System with the 35 mm cameras, Canon IS3 and the Canon 700D, to capture the image information, it was then edited on the computer using Motion 5 and Final Cut Pro X programs. We are presenting several actions in the digital holographic space. The figures are in dialogue within the holographic space and the viewer, in front of the holographic plate. In holography the time of the image is the time of the viewer present. And that particular feature is what distinguishes digital holography from other media.
Through two temporal modalities, the time of the holographic image (the performance recorded time) and the performance time of the public, we create “a new space for the image”, whose structure is influenced by the holographic images and the public as performer. In the tension between the action space of the participants and the virtual space of holographic images, it exists the time image that goes beyond the issue of the movement and has a direct relationship with the participant’s thought.
In this series of digital holographic images and lenticulars, we are using an old camera Canon IS3 and a new HD Canon, on the HOLOrail, to capture old fashion scenes and other scenes having a “nowadays” look and put them on the surface of the holographic plate.
In this series of digital art holograms and lenticulars, we are examining different kinds of movement inside the digital holographic space explored by Elizabeth Sandford-Richardson, a visual performance artist. During the process of capturing the image, we used the HoloCam Portable Light System, equipped with Canon and Nikon cameras positioned at different heights and angles, in order to improve the rendering of the holographic space. Based on the “Performativity of Performance Documentation” a notion introduced by Philip Auslanderi we revisit some authors that have been working in the “theatrical” practise, mainly in photography, adding the possibility of movement in 3D space. We must realise that the movement of the viewer in front of a digital holographic image creates the performance that he/she is looking at. We should consider the physical space, outside the hologram, and this kind of “performance acts”, also part of the work. In summary, we propose a reflection on the digital holographic space, time, movement and its place in contemporary art.
We present an alternative description of nonlinear cross-phase modulation based on the kinetic equation for photons. The most relevant feature of this new approach is that phase itself is completely ignored. Formal exact solutions and approximate analytical solutions are discussed. Experimental measurements of cross-phase modulation of two-color ultrashort laser pulses propagating in a highly nonlinear photonic crystal fiber reveal a good agreement with the analytical results.
During the Renaissance, man placed himself in a vantage point to organise the sensorial data of the surrounding world
that expressed the supremacy of his viewpoint; the man of the twentieth-first century is looking at the world as a whole
from its orbit, not from inside like the Renaissance man did with perspective, but from outside, to have a entirely new
view and to be able to explore and control it more firmly1.
These concepts are examined and inform a series of Digital Art Holograms and Lenticular technology based on different
geometries for image capture, using the HoloCam Portable Light System, with the Canon camera angled toward the
floor, according different angles and different heights. Based on these geometries, some concepts of time and space are
artistically explored. This artistic concept of time and space explores a method to improve the rendering of holographic
space by designing forms that appear within real space.
The speed at which our world is changing is reflected in the shifting way artistic images are created and produced.
Holography can be used as a medium to express the perception of space with light and colour and to make the
material and the immaterial experiments with optical and digital holography.
This paper intends to be a reflection on the final product of that process surrounding a debate of ideas for new
experimental methodologies applied to holographic images. Holography is a time-based medium and the
irretrievable linear flow of time is responsible for a drama, unique to traditional cinematography. If the viewers
move to left or right, they see glimpses of the next scene or the previous one perceived a second ago. This
interaction of synthetic space arises questions such as: can we see, in "reality", two forms in the same space?
Trying to answer this question, a series of works has been created. These concepts are embryonic to a series of
digital art holograms and lenticulars technique's titled "Across Light: Through Colour". They required some
technical research and comparison between effects from different camera types, using Canon IS3 and Sony HDR
Normal and cancer affected samples of colon tissue have been measured using
transmission time-domain terahertz spectroscopy and continuous wave terahertz
imaging. We show that it is possible to distinguish between normal and cancerous
regions in the samples when they are fixed in formalin or embedded in paraffin. Plots of
the refractive index of normal and cancer affected tissues as well as 2-D transmission
THz images are shown. Experimental results will be presented and the conditions for
discrimination between normal and affected tissue will be discussed.
Authors writing about the portrait insist on the status of extending the model image portrayed beyond the absence and
even death. The portrait also has this ability and suggests immortality. The picture suspends the time, making the absent
The portrait has been, over time, one of the themes mostly used in art. No wonder that in holography it is an important
subject as well. The face is a body area of privileged communication and expression. It expresses emotions through
looks, smiles, movements and expressions. Being Holography, so far, the recording technology that represents the object
most similar to the original, with the same parallax, we may fall into a mimetic representation of reality. On Art
Holography even by following paths already traversed, the resulting holograms are always different because of the
unique concept that each artist-holographer puts into his work. As with any other artistic technology, each artist uses the
medium differently and with different results.
Based on experimental analyses of colon and rectal tissues by THz spectroscopy and THz
imaging, we show it is possible to distinguish between healthy and cancerous zones. Plots of
the absorption coefficient and the index of refraction of the healthy and cancer affected
tissues as well as 2-D transmission THz images will be presented. The experimental results will
be discussed and the conditions for the tissues discrimination will be established.
We propose an electro-optic time-lens (EOTL) model based on the coupled-mode theory. The model describes the
propagation of a femtosecond pulse in an electro-optical crystal with parabolic refractive index modulation by a
microwave. The proposed model integrates the second order dispersion approximation (β2 ≠ 0) and takes into
consideration the possible mismatch between the microwave phase velocity and the pulse group velocity. The coupled-mode
theory uses the Hermite-Gaussian functions which are the modes of an ideal electro-optic time-lens. The model
characterizes completely the performances of EOTL, including the aberrations, and it establishes the maximum velocity
mismatch for which the pulse profile propagates through the crystal without significant distortion. The theoretical model
is numerically implement considering the propagation of a short pulse in a Litium Niobate time-lens.
We demonstrate highly-efficient generation of green-blue light using 20-fs femtosecond laser pulses propagating in short highly-nonlinear photonic crystal fibres. Three 5-mm-long fibres with different zero dispersion wavelengths were pumped by Ti:Sapphire pulses centred around 800-nm, and the relevant spectral characteristics of the generated radiation were studied as a function of pulse energy and chirp. In addition to the non-solitonic green-blue light, a well-defined infrared peak was simultaneously observed that follows the same power and wavelength dependence found on the green-blue peak. This work shows that short photonic crystal fibres can be used as an efficient source of ultrashort blue-green pulses (and possibly near-IR pulses) since linear dispersion (and consequent temporal broadening) and absorption of fused silica are minimized when using short fibres.
We present what is to our knowledge the most complete 1-D numerical analysis of the evolution and the propagation
dynamics of an ultrashort laser pulse in a Ti:Sapphire laser oscillator. This study confirms the dispersion
managed model of mode-locking, and emphasizes the role of the Kerr nonlinearity in generating mode-locked
spectra with a smooth and well-behaved spectral phase. A very good agreement with experimental measurements
of pulse energy, spectrum, and temporal width of extracavity compressed pulses is found.
The production of high-energy ultra-short laser pulses in gas-filled hollow fibres is now a well-established technique.
Below a specific critical power, the smoothness of spatial and temporal profiles of input pulses is not perturbed during
propagation. However, gas ionization and pulse filamentation occur above that critical power strongly disrupting the
pulse profiles. Both propagation regimes in argon are numerically studied for two different propagation configurations:
free gas and gas filled hollow fibre. Below critical power it is shown the pulse is spectrally broadened while maintaining
smooth temporal and spatial profiles. Otherwise, these quantities show strong variations.
We report on the efficient spectral control of ultrashort sub-nanojoule violet laser pulses by means of cross-phase modulation (XPM) with a pump pulse in a highly nonlinear photonic crystal fiber (PCF). Spectra of the output pulses were recorded as a function of pump-probe delay for different pump central wavelengths. For fiber lengths that are much longer than the pulse walk-off distance, we consistently observe simultaneous downshifted and upshifted bands in the output pulses, associated with the frequency shift induced by both the leading and trailing edges of the pump as it sweeps over the probe pulses. These features can only be observed with pump pulses propagating in the anomalous dispersion region of the PCF, where pump pulse compression occurs and provides the necessary pump asymmetry.
The different concepts of artistic holography have contributed to the development of new ways of understanding reality.
Holography makes it possible to express different visions of the recorded subject. In this work, from a primary portrait
recorded with a pulsed ruby laser, a new kind of portrait will be created. The extremely realistic image of the master
hologram will be transformed in a secondary expressionist multicoloured hologram. Using an emulsion manipulating
technique before exposure, the portrait is changed, in order to achieve new visions of reality.
Holography related activities in Portugal have been mainly concentrated in the areas of scientific research, teaching and fine arts. These activities take place in different laboratories located at Universities of Porto/ CETO (Centro de Ciências e Tecnologias Opticas), Aveiro, Lisboa and Covilhä, research centers and institutes, like INETI (Instituto Nacional de Engenharia e Tecnologia Industrial). The holographic principles and technologies are taught in graduate and undergraduate courses. Seminars, workshops, talks and exhibitions are organized regularly to the specialists and the general public.
A multicolor holography study case will be presented with emphasis on color control in different silver-halide materials. It has been systematized in order to compare the results obtained with Agfa 8E 75HD to those with Slavich PFG-01. Some experiments were made and the emulsion was manipulated before exposure to achieve high quality multicolored white light reflection holograms. This work has therefore been developed in order to obtain the various colors in a very well controlled way.
A new type of diffractive optical element, a single layered binary grating producing only three diffraction orders, with equal efficiency, is presented. Its design, in the regime of quasi sub-wavelength, is based on rigorous coupled-wave analysis. A theoretical study and experiment of the grating fabrication errors effects and tolerances is also presented.
Artists have always employed color in a personal and expressive way using several different materials. Display holography is being used by artists as an instrument for creation and therefore the study of holography techniques is necessary. In holography, instead of pigments the artist uses pure light. Color in holography based on artistic purposes can not be merely a coincidence but an intentional choice, so it is important for an artist to be able to anticipate a particular final color result. Some color holography techniques will be presented and discussed.
The coherent filtering effects caused by the uniform transverse movement of an object or an imaging lens are studied and experimentally demonstrated using holography. It is shown that for the same displacement, the cutoff frequency is the smallest in the case of the imaging lens movement. Experimental results and theory are presented, with apparent agreement.
A concept - holotag, of an automatic holographic-aided identification label is presented with comparative
Technological challenges met on the concept experimental implementation are reviewed. The label carried
information is first transposed with a 2-D interleaved self-correcting spatial coding into a plane binary
object patch pattern.
Then recorded in the form of a computer generated Fourier hologram, spatially multiplexed- holotag, onto an
optical recording material-Digital Paper, laminated and protection covered. Image processing techniques
followed by decoding procedures regenerate the original data despite process incurred degradations.