Jean-Louis de Bougrenet de la Tocnaye's research while affiliated with IMT Atlantique and other places
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Publications (90)
In this paper, we present some thoughts about the recent developments, made possible by technological advances and miniaturisation of connected visual prostheses, linked to the visual system, operating at different level of this one, on the retina as well as in the visual cortex. While these objects represent a great hope for people with impaired v...
Date de dépôt : 19/03/2021N° de dépôt : FR2102785
Oculometric data, such as gaze direction, pupil size and accommodative change, play a key role nowadays in the analysis of cognitive load and attentional activities, in particular with the development of Integrated Visual Augmentation Systems in many application domains, such as health, defense and industry. Such measurements are most frequently ob...
This paper describes a camera-less eye-tracker using an instrumented contact lens fitted with photodetectors and illuminated by an eyewear. The gaze direction is computed on the lens using the photo-currents by means of a mixed signal 0.35-µm CMOS ASIC. NFC is used to power the ASIC and to transmit the gaze direction to the eyewear. Experimental mea...
We present a new eye-tracking and target designation device based on a contact lens incorporating a pair of vertical-cavity surface-emitting lasers (VCSELs). We describe the operating principle, the manufacturing process and characterize the impact of the VCSELs encapsulation on their optical properties. We then describe how such device can be inco...
Copropriétaire : VALEO / E3SDate de dépôt : 03/11/2020
Copropriétaire : LCSDate de dépôt : 07/07/2021N° de dépôt : PCT/EP2021/068906
We present the design, fabrication, and test of a multipurpose integrated circuit (Application Specific Integrated Circuit) in AMS 0.35 µm Complementary Metal Oxide Semiconductor technology. This circuit is embedded in a scleral contact lens, combined with photodiodes enabling the gaze direction detection when illuminated and wirelessly powered by...
Date de dépôt : 10/05/2021N° de dépôt : PCT/EP2021/062279
We present an innovative augmented reality display to project information on the perifovea. Our system uses a contact lens embedding various diffractive optical elements (DOE) and switchable light sources. The DOEs are located at the iris periphery, keeping the visual axis free of any disturbance while allowing AR content projection onto the perifo...
Date de dépôt : 21/01/2021N° de dépôt : PCT/EP2021/051357
Concerns about head mounted displays have led to numerous studies about their potential impact on the visual system. Yet, none have investigated if the use of Virtual Reality (VR) Head Mounted Displays with their reduced field of view and visually soliciting visual environment, could reduce the spatial spread of the attentional window. To address t...
Purpose: Virtual Reality (VR) headsets are becoming more and more popular and are now standard attractions in many places such as museums and fairs. Although the issues of VR induced cybersickness or eye strain are well known, as well as the associated risks factors, most studies have focused on reducing it or assessing this discomfort rather than...
We present analytical and experimental results of the microstructuring of movie theater metallic screens. Our objective is to maintain the polarization state of reflected light and to control the distribution of light intensity avoiding hotspots. We derive analytical solutions of surface functions with an axial symmetry (kernel) that produces isotr...
Date de dépôt : 15/04/2020N° de dépôt : PCT/EP2020/060541
The recent advances in wearable technologies had caused a surge in the demand for stretchable Li-ion microbatteries. Herein, a special design based on micropillar electrodes supported on metallic serpentines has been investigated to achieve the fabrication of a functionning device. Besides achieving high areal capacity values like 2.5 mA h cm⁻² at...
Most current eye-trackers are camera-based and rely on image processing. To improve gaze tracking accuracy, this paper presents a new approach based on a camera-less gaze tracking system using a smart contact lens. A scleral lens is fitted with photodetectors illuminated by specific spectacles. Photo-currents vary with eye movements as the light ph...
Purpose
Blinking plays an important role in protecting the eyes, and the use of computers has been associated with a reduction in the blink rate. The goal of this study was to evaluate the effect of a virtual reality headset on blinking and lipid layer thickness and to compare these data to those associated with a conventional desktop monitor.
Met...
We study the effect of viewing directions in projection-based multiviewer display systems. Such systems display different images to several users watching a common screen. While different separation techniques have been used in cinema, we are interested in applications that require a more demanding viewing angle and more independent views, such as...
Date de dépôt : 03/04/2019N° de dépôt : PCT/EP2019/058355
In this paper, we demonstrate the first attempt of encapsulating a flexible micro battery into a contact lens to implement an eye-tracker. The paper discusses how to scale the battery to power various circuits embedded in the contact lens, such as ASIC, photodiodes, etc., as well as how to combine the battery with external harvested energy sources....
This work investigates the improvement of transmittance dynamic and response time of low viscosity nematic liquid crystals, combined with neutral dichroic dyes, by the addition of chiral dopants, while maintaining a low Haze value. We present some experimental results showing the impact of the addition of these chiral dopants on both dichroic effic...
We propose an attempt of explanation for the improvement of the transmittance dynamic of nematic liquid crystals, combined with neutral dichroic dyes, by the addition of chiral dopants. It is based on a fine polarimetric analysis of the liquid crystal medium, using the Mueller matrix formalism. This enables us to determine the polarization mode pro...
Date de dépôt : 15/12/2016N° de dépôt : EP16816650.2
We present a method for designing spectral interference filters optimized for different kinds of projectors for three-dimensional (3-D) projection systems. Among the parameters considered, the color balance, the transmission efficiency, and the filter isolation are critical and should be optimized in such a way that color correction is no longer ne...
Stereopsis is not only the perception of static depth information, but also involves the ability to detect dynamic stereoscopic motion. This study investigated the motion-in-depth (MID) perception in dynamic random dot stereogram (DRDS) among the population of inexperienced normal vision observers, and the role of visual perceptual training for MID...
Random-dot stereograms have been widely used to explore the neural mechanisms underlying binocular vision. Although they are a powerful tool to stimulate motion-in-depth (MID) perception, published results report some difficulties in the capacity to perceive MID generated by random-dot stereograms. The purpose of this study was to investigate wheth...
Copropriétaire : E3SDate de dépôt : 29/02/2016N° de dépôt : PCT/EP2016/054120
Purpose:
We investigated the impact of target properties on vertical fusion amplitude (VFA) using a 3D display platform; the performance of the subjects allowed us to assess how central and peripheral retina regions interact during the fusion process.
Material and methods:
Fourteen subjects were involved in the test. VFA was recorded by varying...
Salinity is the essential parameter for ocean dynamics studies. Its definition and using in the equations used to calculate the thermodynamic properties of seawater, were revised in 2010, opening the possibility of new sensors developments. In this context, NOSS (NKE Optical Salinity Sensor) has emerged as one of the first underwater instrument for...
Copropriétaire : E3SDate de dépôt : 22/05/2015N° de dépôt : PCT/EP2015061449
We exploit an absorption-scattering based high pitch length cholesteric liquid crystal active shutter. Using the two said fundamental optical properties, we have shown the resultant impact on optical transmission (ON & OFF state) is attracting the general lighting applications. Furthermore, the potential to be used as 3D active optical shutter has...
A novel electro-optical up-conversion mixer architecture comprising four electro-optical phase modulators situated in the arms between an interconnected 1 × 4 distribution tree and a complementary 4 × 2 combination tree is proposed. The distribution and combination trees are based on multi-mode interference couplers (MMI). The novelty lies in the u...
A photonic circuit design for implementing frequency 8-tupling and 24-tupling is proposed. The front- and back-end of the circuit comprises 4×4 MMI couplers enclosing an array of four pairs of phase modulators and 2×2 MMI couplers. The proposed design for frequency multiplication requires no optical or electrical filters, the operation is not limit...
Date de dépôt : 22/05/2014N° de dépôt : PCT/EP2014060514
An optical shuttering device is provided, which includes an optical cell with a liquid crystal material between first and second transparent substrates and controlled by an electronic switching circuit. The switching circuit includes a power supply module, providing a control voltage, and a switching element mounted in series between the power supp...
A system for displaying N multimedia streams, including multiple pairs of viewing spectacles and a displaying medium.
In this paper, we discuss various technical options to implement 3D dual-view systems, from four frames generated by two triggered or non-triggered 3D projectors. Such a technique offers 3D free-viewpoint capabilities for two viewers. We compare two different technical implementations based on transmissive video projection and reflective silver scr...
Salinity and turbidity are two important seawater properties in physical oceanography. The study of physical oceanography requires a compact high-resolution in situ salino-turbidimeter to measure these two parameters in different ocean zones. Refractometry has proved to be an effective method to measure seawater salinity with a high resolution. Pre...
A method is provided for manufacturing an electrooptic cell, which includes two plates of optically transparent material and at least one thickness of a composite gel based on a smectic liquid crystal and on a polymer provided between the plates, wherein the gel is in a smectic phase at ambient temperature. The method includes injecting a mixture o...
In this paper we discuss under which conditions standard stereo visual acuity tests can be implemented on 3D TV monitors. In particular, we emphasize the role of environmental lighting conditions, on the measurement of the stereo visual acuity, when using conventional Stereoscopic 3D tests, such as Wirt stereotests. We investigate the impact of par...
Annular linear diffractive axicons are optical devices providing chromatic imaging over an extended depth of focus when illuminated by a white light. To improve their low radiometric performance, multiple annular linear diffractive axicons (MALDAs) have been introduced. Their chromatic properties are well known and constrained by dispersion laws. A...
revue bimestrielle de la SFO (Société Française d'Optique) , éditée par EDP Sciences - rubrique "Cahier technique"
Large-aperture linear diffractive axicons are optical devices providing achromatic nondiffracting beams with an extended depth of focus when illuminated by white light sources. Annular apertures introduce chromatic foci separation, making chromatic imaging possible despite important radiometric losses. Recently, a new type of diffractive axicon has...
CapilR is an experimental platform specializing in Radio-over-Fibre technologies for enhanced wireless access networks. Ongoing activities include the design of radio-over-fibre transceivers at 2.4 GHz for enhanced Wi-Fi coverage in in-building environments, the optical generation and distribution of RF carriers at millimetre-wave frequency ranges...
A vision for developing Brest as a digital city is presented within the framework of the CapilRTram project. This projects aims at deploying state-of-the-art technologies to provide free Wi-Fi access to passengers inside the tram together with a multimedia platform through the exploitation of an optical network infrastructure along the tramway line...
We propose a chromatic analysis of multiple annular linear diffractive axicons. Large aperture axicons are optical devices providing achromatic nondiffracting beams, with an extended depth of focus, when illuminated by a white light source, due to chromatic foci superimposition. Annular apertures introduce chromatic foci separation, and because chr...
A position sensitive device (PSD) is frequently used in laser beam deviation measurement. However, it lacks the capability to retrieve the power distribution information of a laser beam. A charge-coupled device (CCD) gives much more information of a laser beam than a PSD. The requirement of a multifunctional sensor makes the replacement of a PSD wi...
Techniques for optical generation of millimetre-wave RF carriers are presented. In particular, integrated semiconductor lasers based on lateral coupling of optical modes in a distributed feedback structure are discussed together with preliminary experimental results.
Measurement of seawater salinity, with a high accuracy,has become a key issue in ocean control. One of the mostdirect ways is to measure the seawater refractive indexwhich can be then related to the salinity. Refractometry is the most direct and simplest way to measure refractive index. Recent advances in high resolution position sensitive devices...
By using soluble fullerene derivative [60]PCBM, we improved photorefractive efficiency in polymer-liquid crystal composites in comparison to previous works on similar materials. We show the effect of polymer network results in resolution and bandwidth improvements compared to pure liquid crystals. This is explained by the introduction of a charge t...
We present a new generation of liquid crystal shutters for active glasses, well suited to 3-D cinema current trends, involving triple flash regimes. Our technology uses a composite smectic C* liquid crystal mixture1. In this paper we focus on the electro-optical characterization of composite smectic-based shutters, and compare their performance wit...
We investigate how to scale a free-space wavelength blocker to implement a spectral phase scrambling system to secure high data rate optical transmissions within a wavelength division multiplexing optical network. This technique belongs to the optical code-division multiple access family, and its implementation can be carried out using a free-space...
We propose to induce a two-dimensional (2D) periodic modulation structure into a planar Grandjean cholesteric liquid crystal (CLC) to demonstrate the intrinsic 2D photonic crystal properties of such materials. The structure combines a thin transmission grating and a Bragg reflective grating. One advantage of using CLC is the intrinsic high quality...
This paper reports on the experimental observation of the displacement of a surface plasmon resonance (SPR) excited by a metallic diffraction grating. This effect is achieved by the use of an electro-optical material composed of nano-sized droplets of liquid crystals dispersed in a host polymer. The average refractive index of this material in the...
We present the first vertical surface emitting laser (VCSEL) operating at 1.55-μm comprising a electro-optic modulator inside its cavity. This material consists of nematic liquid crystal dispersed in a polymer material (nano-PDLC). This first VCSEL exhibits a 10 nm tuning range and an excellent side-mode suppression ratio higher than 20 dB over the...
We propose an optimized structure of a tunable and reconfigurable microwave-photonics filter. The structure exploits the capability of a high-precision dynamic-gain equalizer (DGE) to modify the optical spectrum of the broadband light source of a slicing filter. Independent tunability and reconfigurability is obtained due to the optimization of the...
The optimization of the experimental parameters of two multiplexed holographic transmission gratings recorded in holographic polymer-dispersed liquid crystals is investigated. Two methods are used to record the holograms: simultaneous and sequential multiplexing. These two processes are optimized to produce two multiplexed Bragg gratings that have...
We report the design and fabrication of a chirped switchable reflective grating (CSRG) recorded in a holographic polymer-dispersed liquid-crystal material. This CSRG is a spatial wavelength-selective flattener in a free-space dynamic gain equalizer for use in wavelength-division multiplexing (WDM) networks. Prelimenary experimental results show tha...
A new formulation of a multiplex filter for filtering-based optical processors, based on the VanderLugt architecture, is presented. The multireference binary phase-only filter (MBPOF), optimized by regions of support (ROS), constitutes a formal rewriting of some multiplex or composite filters including optimization functions, such as the distributi...
Communications Optiques (1): Nouvelles Technologies Photoniques
Abstract We present the principle of a fast liquid crystal end-less polarisation controller for first order polarisation mode dispersion
compensation (pmd). We demonstrate how this device can be used as a variable and rotatable wave-plate and the resulting advantages to optimize
the complexity of polarisation tracking algorithms. We give some exper...
This paper addresses the issue of using conventional liquid crystal materials as reconfigurable holographic or diffractive
phase elements within optical space switches and the resulting constraints in their choice and use in a telecommunication
environment. We discuss the advantage of this technology for implementing holographic-based approaches wi...
In this paper, we present a new, potentially low cost, robust, and high speed wavelength tunable vertical cavity surface emitting laser (VCSEL) operating at . Tunability is obtained by the modulation of an electric field applied to an electro-optic phase modulator using nano polymer dispersed liquid crystal (nano-PDLC) material. A 30 nm tuning rang...
We propose an optical apparatus enabling the measurement of spherical power, cylindrical power, and optical center coordinates of ophthalmic lenses. The main advantage of this new focimeter is to provide a full bidimensional mapping of the characteristics of ophthalmic glasses. This is made possible thanks to the use of a large-area and high-resolu...
We propose and demonstrate an endless polarization controller that uses the electroclinic effect in the smectic A* phase with homeotropic orientation. This kind of device has a great importance in optical telecommunications for polarization mode dispersion compensation, polarization multiplexing or to compensate polarization dependent losses. Its m...
In the framework of optical transport networks based on wavelength division multiplexing, (WDM), one of the most critical elements is the optical cross-connect [1] (OXC). At the core of many cross-connect architectures is a space-switching stage, operating in the 1.55 telecom wavelength window. An important feature is that the device routing peform...
The purpose of this paper is to investigate the performance of microoptics for telecommunication systems using free-space
interconnects. This concerns mainly distribution or switching and routing tasks. In order to evaluate the interconnection
capability of free-space microoptics, we impose severe conditions on the interconnects. These conditions c...
Citations
... other eye-tracking research samples [29][30][31][32][33][34][35][36][37][38]. We established the "problem discoverability" (p) at 0.05 and the "problem discovery goal" (P (x ≥ 1)) at 0.95, and applied the formula: ...