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RESEARCH
Main achievements of the project
We designed and created a photoplotter based
on polylithographic techniques for which
reconfigurable masks replace the usual
photomasks. These masks, reconfigurable in
real time, are usually LCD (Liquid Crystal
Display) or DMD screens, used as spatial ligh
modulators. Compared with the LCD, the DMD
used in our application presents the further
advantage of working in reflection (which makes
it less dependent on the wavelength) and of being
able to work in UV. We use it between 300 and
400 nm. The photoplotter is used for direct
photo-inscription of integrated optical function
into polymers and/or of diffractive elements. It is
particularly adapted to the prototyping of
diffractive elements and/or the creation of small
series. For the study and commercialization of
these elements, Holotetrix, (PME) which is a
spin-off the optics department, benefits from the
high performance of this new photoplotter.
Thanks to the improvement and modification of
existing characterization benches, the optics
department has been able to fulfill its
obligations, within the framework of the «
Newton » European project, by carrying out a
study of the optical structure and performance
(spectral response from 400 to 1700nm) of
samples of 3D photonic crystals made by our
partners in this project. Notably, we managed to
measure the spectrum of samples of just a few
100 square microns and simultaneously to
visualize on a CCD camera the responses from
the different parts of these structures during the
measurement of their spectral transmission and
reflection. Using the photoplotter described
above, we are now also taking part in improving
the manufacture of these 3D photonic crystals.
A new type of compact refractometer was
created to measure the refractive index of sea
water. This measurement is useful in
oceanography for calculating the oceans’ density
and salinity from empirical relations. Compared
with conductivity sensors, currently used as
salinometers, .this refractometer presents less
dependence on temperature and greater
precision when estimating absolute salinity. The
resolution on the refractive index measurement
is ±4 10-7 which corresponds to a resolution of
±2 10-3 g/kg.
We have a CIFRE contract to work with INDUCT
(private company) for the supervision of a
doctoral thesis on : "Reconnaissance et analyse
automatique, temps réel de signalisations
routières optiques."
(Recognition and automatic analysis, real time of
optical road signs). Recognition and geopositioning
of horizontal (white lines) and vertical
(signs) road signaling which is done by the use of
cameras and processors on-board a vehicle
which make it possible to address different
problems such as evaluating the existing road
network, assessing the relevance of road signs
and markings according to the environment and
driver-aid systems etc. The work undertaken for
the thesis led to the creation of a subsidiary : «
Viamétris » which proposes an automated
recognition tool for the analysis of the road
network. This CIFRE contract partnership will be
coming to an end in 2009 and we are seeking to
prolong this skill in the perception and analysis
of the roadways environment by making new
contracts and fresh assignments such as
imaging after propagation in a diffusing
environment (fog).
Publications
Articles in peer-review journals
(1) Christiane Carré, Roma Grzymala. Matériaux pour l'optique. Contrôles
Essais Mesures, octobre 2008, n° 25, pp. 7
(2) Nolwenn Dissaux, Kevin Heggarty, Christiane Carré, Andrei
Lavrinenko, Thorsten Schweizer, Wendel Wohlleben. Matériaux pour
l'optique : caractérisation de structures de type cristaux photoniques
obtenues par déposition colloïdales. Contrôles Essais Mesures, octobre
2008, n° 25
Thesis
[3] Mélanie Kessels. Conception, modélisation, développement et
application d'un phototraceur massivement parallèle pour l'écriture
directe de structures submicroniques. Th. doct. : Sciences pour
l'ingénieur : Institut Télécom ; Télécom Bretagne : 2008, 2008telb0069.
198 p.
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