An application driven comparison of depth perception on desktop 3D displays.

Desktop 3D displays vary in their optical design and this results in a significant variation in the way in which stereo images are physically displayed on different 3D displays. When precise depth judgements need to be made these differences may become critical to task performance. Applications where this is a particular issue include medical imaging, geoscience and scientific visualization. We investigate perceived depth thresholds for four classes of desktop 3D display; full resolution, row interleaved, column interleaved and colour-column interleaved. Given the same input image resolution we calculate the physical view resolution for each class of display to geometrically predict its minimum perceived depth threshold. To verify our geometric predictions we present the design of a task where viewers are required to judge which of two neighboring squares lies in front of the other. We report results from a trial using this task where participants are randomly asked to judge whether they can perceive one of four levels of image disparity (0,2,4 and 6 pixels) on seven different desktop 3D displays. The results show a strong effect and the task produces reliable results that are sensitive to display differences. However, we conclude that depth judgement performance cannot always be predicted from display geometry alone. Other system factors, including software drivers, electronic interfaces, and individual participant differences must also be considered when choosing a 3D display to make critical depth judgements

Cosmic cookery : making a stereoscopic 3D animated movie.

This paper describes our experience making a short stereoscopic movie visualizing the development of structure in the universe during the 13.7 billion years from the Big Bang to the present day. Aimed at a general audience for the Royal Society's 2005 Summer Science Exhibition, the movie illustrates how the latest cosmological theories based on dark matter and dark energy are capable of producing structures as complex as spiral galaxies and allows the viewer to directly compare observations from the real universe with theoretical results. 3D is an inherent feature of the cosmology data sets and stereoscopic visualization provides a natural way to present the images to the viewer, in addition to allowing researchers to visualize these vast, complex data sets. The presentation of the movie used passive, linearly polarized projection onto a 2m wide screen but it was also required to playback on a Sharp RD3D display and in anaglyph projection at venues without dedicated stereoscopic display equipment. Additionally lenticular prints were made from key images in the movie. We discuss the following technical challenges during the stereoscopic production process; 1) Controlling the depth presentation, 2) Editing the stereoscopic sequences, 3) Generating compressed movies in display speci¯c formats. We conclude that the generation of high quality stereoscopic movie content using desktop tools and equipment is feasible. This does require careful quality control and manual intervention but we believe these overheads are worthwhile when presenting inherently 3D data as the result is signi¯cantly increased impact and better understanding of complex 3D scenes

An application driven comparison of depth perception on desktop 3D displays

Desktop 3D displays vary in their optical design and this results in a significant variation in the way in which stereo images are physically displayed on different 3D displays. When precise depth judgements need to be made these differences may become critical to task performance. Applications where this is a particular issue include medical imaging, geoscience and scientific visualization. We investigate perceived depth thresholds for four classes of desktop 3D display; full resolution, row interleaved, column interleaved and colour-column interleaved. Given the same input image resolution we calculate the physical view resolution for each class of display to geometrically predict its minimum perceived depth threshold. To verify our geometric predictions we present the design of a task where viewers are required to judge which of two neighboring squares lies in front of the other. We report results from a trial using this task where participants are randomly asked to judge whether they can perceive one of four levels of image disparity (0,2,4 and 6 pixels) on seven different desktop 3D displays. The results show a strong effect and the task produces reliable results that are sensitive to display differences. However, we conclude that depth judgement performance cannot always be predicted from display geometry alone. Other system factors, including software drivers, electronic interfaces, and individual participant differences must also be considered when choosing a 3D display to make critical depth judgements

Terahertz Spectroscopy of Protein Solutions

A silicon-compatible photonics microsystem for THz probing of proteins is discussed. THz-FTIR measurements of protein aqueous solutions show the viability of the technique and allow for estimation of optimal concentrations and path-lengths of liquid samples, which is important for the design of the proposed THz-sensing chip

Hybrid nanostructured supports for Surface Enhanced Raman Scattering

Porous silicon solid supports with pore diameter 0.5-1 microns, infiltrated with Ag nanostructures for Surface Enhanced Raman Scattering, were prepared according to two procedures: spontaneous Ag+ reduction on the surface of freshly etched porous silicon immersed in Ag+ aqueous solutions , or anchoring colloidal Ag nanoparticles on the surface previously functionalized by aminosilane. Using rodhamine-6G as analyte the detection limits were of the order of 20 micro-M and 20 nano-M with porous silicon metalized by the first and second procedure, respectively. This large increase of sensitivity notwithstanding a reduced surface density of rodhamine-6G obtained on porous silicon metalized by the second procedure is discussed in terms of better hot spot efficiency and reduced aspecific binding out of the hot regions obtained depositing the colloids on the aminosilane functionalized surface

Silicon oxynitride waveguides as evanescent-field-based fluorescent biosensors

Channel waveguide-based evanescent-field optical sensors are developed to make a fully integrated chip biosensor. The optical system senses fluorescent analytes immobilized within a micrometric sized bioreactor well realized within an optical waveguide. The main novelty of this work is related to the fact that, within the bioreactor well, the excitation of the fluorescent signal is achieved by means of the evanescent field propagating through a silicon oxynitride waveguide. The immobilization of the emitting molecules is realized by functionalization of the waveguide surface by a wet chemical method. These photonic biosensors are successfully applied to detect low surface concentration (10−11 mol cm−2) of a green emitting organic dye. This approach could permit the selective detection of a wide range of chemical and biological species in complex matrices and can be exploited to set-up array-based screening devices. In this regard, the preferential excitation of the dye molecules in the close vicinity of the exposed waveguide core is also analysed