Denis Gindre

Denis Gindre
University of Angers | UA · Département de Physique

Professor

About

77
Publications
7,874
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1,574
Citations
Introduction
Denis Gindre currently works at the Département de Physique, University of Angers. Denis does research in Optics, Materials Science and Materials Physics.
Additional affiliations
August 2006 - present
University of Angers

Publications

Publications (77)
Article
Halide perovskites exhibiting broad band emission have attracted increasing attention since their discovery in 2014 because of their potentiality in lighting applications. Here, we report a new bromoplumbate organic-inorganic perovskite...
Article
Full-text available
The recent development of 3D printers allowed a lot of limitations in the field of microfabrication to be circumvented. The ever-growing chase for smaller dimensions has come to an end in domains such as microfluidics, and the focus now shifted to a cost-efficiency challenge. In this paper, the use of a high-resolution stereolithography LCD 3D prin...
Preprint
Full-text available
The recent development of 3D printers allowed a lot of limitations in the field of microfabrication to be circumvented. The ever-growing chase for smaller dimensions has come to an end in domains such as microfluidics, and the focus now shifted to a cost-efficiency challenge. In this paper, the use of a high-resolution stereolithography LCD 3D prin...
Article
Full-text available
The use of cyclopropenone derivatives as latent photo-released strained cyclic alkynes is reported for the covalent printing of complex patterns on cellulose paper. Two different approaches using either a UV LED or a laser as light irradiation source are discussed. While the high intensity of the laser damages the grafted molecular layer, the use o...
Article
Full-text available
This study describes the adaptation of non-linear microscopy for single-particle tracking (SPT), a method commonly used in biology with single-photon fluorescence. Imaging moving objects with non-linear microscopy raises difficulties due to the scanning process of the acquisitions. The interest of the study is based on the balance between all the e...
Conference Paper
This work presents second-order nonlinear optical investigations of Ba(NO 3 ) 2 /Al 2 O 3 crystalline nanocomposite. Studied sample was obtained by crystal growth in nanoporous Al 2 O 3 membrane. Nonlinear optical studies were characterized by means of second harmonic generation via Maker fringe method and by SHG surface imaging. Additionally, surf...
Article
The present work takes advantage of the self-assembly process occuring along organogelation, to organize Second Harmonic Generation (SHG) active chromophores. To do so, three push-pull chromophores endowed with a dodecyl urea chain were synthesized and characterized. Their organogelating properties were studied in a wide range of solvents. Despite...
Article
Full-text available
The synthesis of a molecule constituted of two diarylamine-based push-pull chromophores covalently linked via their nitrogen atom is described. Comparison of the electronic properties with the parent monomer shows that dimerization has negligible influence on the electronic properties of the molecule but exerts a dramatic impact on the capacity of...
Article
Full-text available
A study of the structural parameters which govern the supramolecular organization of an organogelator built from the Disperse Red moiety is proposed. In particular, the key balance between intermolecular H-bonding and/or π-π interactions is addressed by comparing the effect of a secondary amide vs. an ester linker within the molecular structure. So...
Article
An organogelator based on the Disperse Red NLO-phore was synthesized according to a simple and efficient three-step procedure. The supramolecular gel organization leads to xerogels which display a spontaneous second harmonic generation (SHG) response without any need for pre-processing and this SHG activity appears stable over several months. These...
Article
Full-text available
Optical data storage was performed with various thin polymer films containing coumarin-based derivatives and by using femtosecond laser pulses as well as two-photon absorption processes. Exploring the photodimerization attribute of coumarin derivatives and using appropriate irradiation wavelengths, recording/erasing processes could be carried out i...
Article
A small push-pull molecule involving a diphenylamine substituted by an oligo-oxyethylene chain is described. The compound exhibits aggregation-induced emission with solvent-dependent emission wavelength. Spun-cast deep-red amorphous films rapidly self-reorganize into colorless crystalline films which exhibit mechanofluorochromism and aggregation-in...
Article
New poly(methyl methacrylate)s bearing push-pull azo-moieties, with the azo-dye content ranging from 31 wt% to 100 wt%, are synthesized by (co)polymerization of a methacrylamide-based azo-monomer. The high reactivity of the colored monomer allowed well-balanced structures to be achieved, characterized by a suitable thermal stability. The second har...
Article
Glial tumors are primary tumors of the central nervous system. Gross total resection (GTR) of the tumor is the first step of its therapeutic management. Several techniques of per-operative analysis of the margin of the peritumoral brain zone (PBZ) have been developed in order to ensure a GTR of the tumor. We present here a new approach to the per-o...
Article
We report on a crystalline rotor that undergoes a reversible phase transition at 145 K. Variable-temperature X-ray and 1H spin−lattice relaxation experiments, and calculations of rotational barriers, provide a description (i) of the way in which the rotators' dynamics changes back and forth at the onset of the phase transition and (ii) of the mecha...
Article
Full-text available
We report on a polymorph (2) of an amphidynamic crystal of molecular rods with two helical 1,4-bis(ethynyl)bicyclo[2.2.2]octane rotators where half of the rod-like molecules appear to be shifted with respect to their closest neighbours. This translation takes cogwheel-like pairs of rotators apart in the lattice in such a way that their motion becom...
Article
Bi2ZnOB2O6 nonlinear optical single crystals were grown by means of the Kyropoulos method from stoichiometric melt. The second and third harmonic generation (SHG/THG) of Bi2ZnOB2O6 crystals were investigated by the SHG/THG Maker fringes technique. Moreover, SHG microscopy studies were carried out providing two-dimensional SHG images as a function o...
Article
Full-text available
We report a technique to encode grayscale digital images in thin films composed of copolymers containing coumarins. A nonlinear microscopy setup was implemented and two nonlinear optical processes were used to store and read information. A third-order process (two-photon absorption) was used to photoinduce a controlled dimer-to-monomer ratio within...
Conference Paper
We present recent work concerning the 3D optical data storage in thin organic films by means of nonlinear processes: cross-linking of coumarins photoinduced by two-photon absorption (TPA) to write information into the material, and the Second Harmonic generation (SHG) microscopy for the read-out. The study has been carried out with a Ti:sapphire la...
Article
The rod-like molecule bis((4-(4-pyridyl)-ethynyl)bicyclo[2.2.2]oct-1-yl)buta-1,3-diyne, 1 contains two 1,4-bis(ethynyl)bicyclo[2.2.2]octane (BCO) chiral rotators linked by a diyne fragment and self-assembles in a one-dimensional, monoclinic C2/c centrosymmetric structure where two equilibrium positions with large occupancy imbalance (88% versus 12%...
Article
The second-order nonlinear optical properties of photocross-linkable coumarin-based copolymers were investigated using the optical second harmonic generation (SHG) with the Maker fringes technique. High quality and transparent spin-deposited thin films of various methacrylic copolymers containing 4-methylcoumarin pendant chromophores were prepared...
Article
Full-text available
In this work, we present the third order nonlinear optical investigation of two gold complexes, which differ by the nature of the counter cations. The impact of the different design in the architecture through a set of hydrogen bonds in the case of Au-Mel of the systems on the nonlinearity has been studied by means of the Z-scan setup under 532 nm,...
Article
Full-text available
We present the nonlinear absorption investigation of an electroactive ligand and two ruthenium and iron metal complexes under 532 nm, 30 ps laser excitation, by the "open aperture" Z-scan technique. Significant nonlinear optical parameters have in all cases been measured, while the nonlinear attribute has been found to change from saturable to reve...
Article
The nonlinear optical response of a series of azo-containing side-chain polymers is investigated using Z-scan technique, employing 35 ps and 4 ns laser pulses, at 532 nm. The systems were found to exhibit strong nonlinear optical response, dominated by nonlinear refraction. In all cases, the nonlinear absorp-tion and refraction have been determined...
Article
Full-text available
The nonlinear optical (NLO) properties of novel styrylquinolinium dye thin films for photonic applications have been studied by the Z-scan, second harmonic generation (SHG), and third harmonic generation (THG) techniques, providing both the second- and third-order nonlinear optical parameters. The styrylquinolinium dye (E)-1-ethyl-4-(2-(4-hydroxyna...
Article
Full-text available
When a single ultrashort light pulse propagates through a birefringent optical fiber, degenerate cross-phase modulation occurs between the two orthogonal linearly polarized components of the pulse. The combined effects of pulse walk-off and degenerate-cross-phase modulation are characterized theoretically and experimentally. They cause asymmetry an...
Article
Comparative study of the nonlinear optical response of pyrrolo- tetrathiafulvalene polygons has been carried out. These materials are of great importance for photonics, because they can be used as building blocks for more complicated molecular systems like rotaxanes, catenanes which are promising candidates for opto-electronic applications like opt...
Article
Full-text available
In this paper, we illustrate new functionalities fornonlinear optical applications of bio-molecular systems. This study presents DNA complex with new ionic surfactants. These surfactants enabled DNA solubility in solvents other than alcohols, like aromatic and chlorinated ones. Composites with two nonlinear optical (NLO) active dyes are subjects of...
Patent
The present invention relates to the technical field of recording media. The information relates more particularly to a reversible recording medium based on optical storage of at least one item of information within a support material, the recording medium comprising at least one layer of support material comprising: base molecules (M) able to...
Article
An optical setup is proposed for the implementation of compressive sensing with coherent images. This setup specifically exploits the natural multiplicative action of speckle noise occurring with coherent light, in order to optically realize the essential step in compressive sensing which is the multiplication with known random patterns of the imag...
Patent
The invention concerns a optical data memory, said memory comprising at least one layer of supporting material, said supporting material including molecules having, in a local zone, a collective state of molecules from at least one first collective state of molecules, and a second collective state of molecules. The invention is characterized in...
Conference Paper
During the last years there is a growing effort in order to synthesize, functionalize and characterize modern molecular systems, which will have enhanced nonlinearities in order to be utilized in modern photonic applications [1]-[3]. The nonlinearities are generally known to be significantly enhanced in systems which exhibit strong charge transfer...
Article
Full-text available
We present the third order nonlinear optical study of tetrathiafulvalene-based molecular corners. Degenerate four-wave mixing measurements have been done to provide information about the magnitude and the origin of the nonlinearity, while the nonlinear absorption has been separately measured by performing "open aperture" Z-scan measurements. The re...
Article
A functionalized polymer film allowing for a complete and straightforward second-harmonic generation (SHG)-assisted high-contrast writing-reading-erasing-writing sequence is proposed. The whole process is supported by the reversible photoinduced dimerization of a coumarin chromophore and enables efficient optical data storage that can be detected o...
Chapter
Full-text available
We study the impact of the level of the speckle noise on data acquisition in a partially polarized coherent imaging system with the presence of a nonlinearity in the imaging sensor characteristic. In perfectly linear acquisition conditions, due to the essentially multiplicative action of the speckle, the image contrast is unchanged as the speckle n...
Article
Photosensitive materials attract many attention due to their potential application in optical devices such as optical data storage, optical communication, ...[1]. Coumarines and their analogues are well-known for their reversible photoinduced cyclodimerisation properties, leading to cyclobutane-based dimers (scheme) [2]. This equilibrium can be tun...
Article
Full-text available
A tunable circularly polarized distributed feedback (DFB) laser based on reflection grating configuration was realized in a solution of 4- (dicyanomethylene)-2-methyl-6-(4-dimethylaminostyryl)-4H-pyran (DCM) doped methanol. Chiral photonic DFB structures with tunable photonic bandgap were generated by controlling the state of polarization of the tw...
Article
Full-text available
The impact of multiplicative speckle noise on data acquisition in coherent imaging is studied. This demonstrates the possibility to optimally adjust the level of the speckle noise in order to deliberately exploit, with maximum efficacy, the saturation naturally limiting linear image sensors such as CCD cameras, for instance. This constructive actio...
Article
Full-text available
We analyze a simple model of a scalar optical wave with partial coherence. The model is devised to describe the influence on the coherence of the wave, of the statistical properties of its random phase, including both the second-order statistics (phase correlation) - which is classic, but also the first-order statistics (phase distribution) - which...
Article
a b s t r a c t We analyze image transmission in a coherent imaging system, in the presence of speckle noise modeled with the family of Gamma probability density functions of varying order. It is demonstrated that speckle noise can improve the transmission of a coherent image. Exact analytical expressions are obtained for both the best achievable p...
Article
We demonstrate the patterning of the quadratic non-linear optical (QNLO) properties in a photopolymerizable resin doped with push–pull chromophores. Advantage is taken of the crosslinking process to perform the patterning directly. QNLO gratings with a period of 8.5 μm have been achieved over areas of a few cm2. This spacing is comparable to the ty...
Article
Full-text available
Tunable distributed feedback (DFB) lasing output based on reflection grating configuration instead of the traditional transmission gating type was realized from rhodamine 6G (R6G)-doped ethanol and DCM-doped methanol. Pure gain coupling and additional index coupling were obtained in R6G-doped ethanol and DCM-doped methanol, respectively. The tuning...
Article
Tunable distributed feedback (DFB) lasing output based on reflection grating configuration instead of the traditional transmission grating type was realized from rhodamine 6G (R6G)-doped ethanol and DCM-doped methanol. Pure gain coupling and additional index coupling were obtained in R6G-doped ethanol and DCM-doped methanol, respectively. The tunin...
Article
Full-text available
La possibilité d'une influence bénéfique du bruit est étudiée sur les performances d'un système imageur non linéaire à seuil, en présence de bruit multiplicatif de type speckie ou de bruit additif comme le bruit thermique, tels qu'on les rencontre en imagerie cohérente et incohérente. Nous montrons, pour ces deux types de bruit, l'existence de régi...
Article
Full-text available
A coherent imaging system with speckle noise is devised and analyzed. This demonstrates the possibility of improving the nonlinear transmission of a coherent image by increasing the level of the multiplicative speckle noise. This noise-assisted image transmission is a novel instance of stochastic resonance phenomena by which nonlinear signal proces...
Article
Full-text available
We have investigated optical data and image storage using polymeric materials functionalized with azo-dye molecules. Azobenzenze copolymers are well suited for two and three-dimensional storage due to their ability to undergo two-photon isomerization. The sample is initially poled to generate a spatially homogeneous second harmonic signal because o...
Article
We present the direct photopatterning of the birefringence and of the quadratic nonlinear optical properties of push-pull chromophore doped photopolymers. We demonstrate stability over to 10000 hours and a 8 mum spatial resolution.
Article
Full-text available
The role of surface plasmon in second harmonic generation from arrays of gold nanorod particles excited by femtosecond laser pulses is investigated as a function of incident light polarization and irradiation wavelength. In addition to photoluminescence, a peak of second harmonic is observed and is found to depend on the polarization and wavelength...
Article
Full-text available
Tunable distributed feedback lasing output based on reflection grating configuration instead of the traditional transmission one was realized from rhodamine 6G (R6G)-doped ethanol and 4-dicyanomethylene-2-methyl-6- (p-dimethylaminostyryl)-4H-pyran-(DCM)-doped methanol. Pure gain coupling and additional index coupling were obtained in R6G-doped etha...
Article
Full-text available
While information encoding through optically induced orientation of azo dyes in organic matrices is being extensively pursued, we propose the alternative of starting out with poled films and to locally reduce their second-harmonic generation capacity by a focused near-infrared femtosecond laser beam of moderate intensity. Arrays of dots irradiated...
Article
Full-text available
We study the dynamics of the emission spectrum of a distributed Feedback Dye Laser in Rhodamine 6G doped polymer films. The optical feedback is provided by Bragg gratings formed in the film by interference patterns created by the pump beams. In this experiment the sample is pumped by two beams in a Lloyd mirror interferometer configuration. Both th...
Article
Full-text available
We present applications of multi-photonic microscopy in two different domains: integrated optics and biophysics. In the first application, we show how to encode information through the detection of second harmonic signals in polymeric films functionalized with azo-dye molecules. In the second application, we use the two photon induced fluorescence...
Article
Full-text available
Organic-inorganic hybrid materials were prepared from an ureasil precursor (ureapropyltriethoxysilane designated as UPTES) and acrylic acid modified zirconium (IV) n-propoxide. Thin films containing rhodamine 6G (Rh6G) were prepared by spin-coating on glass substrates with different Zr:Si molar ratios (Zr:Si = 75:25, 50:50 and 25:75). Refractive in...
Article
Full-text available
We propose to encode optical information through the localized depoling of polar chromophores in thin films of grafted polymeric materials with a femtosecond near IR laser source. This disorientation is promoted through the photoisomerization of the azo-dye component induced by a twophoton absorption process. We show that the resulting localized lo...
Article
Organic materials possessing quadratic non linear optical (NLO) properties are now part of the optical material panel available for applications. Up to now, the patterning of their optical properties for device fabrication is commonly achieved by the lithographic techniques derived from the microelectronic domain. We propose here an alternative met...
Article
Full-text available
We report experimental and theoretical investigations of multiple laser-line emission in a distributed-feedback dye laser pumped by two coherent optical beams. We have used a Lloyd interferometer configuration with second- and third-order Bragg reflections to study the interaction between the two incident pumps in an organic thin film. We demonstra...
Article
Full-text available
We report on transient laser action during the photopolymerization process in organic thin films of acrylate monomers doped with a laser dye. The emission spectrum was monitored over a period of time in the direction orthogonal to the incident laser beam which is kept at a constant intensity during the experiments. The emission spectra display the...
Article
We report on particular features of thin film distributed feedback (DFB) lasers. Devices are optically pumped using a Lloyd-mirror interferometer. For a given DFB grating period, the number of lasing modes is film thickness dependent. Spectral content of the devices is analysed using planar waveguide theory. An excellent agreement between the theor...
Chapter
We present a study of Distributed Feedback (DFB) Laser emission in polymer thin films. This laser scheme permits efficient control of the stimulated emission in dye doped polymer materials. Optical feedback is provided by distributed Bragg gratings formed in the film by interference patterns from the pump beam. We report on particular features of t...
Article
Owing to light confinement, naturally shaped needle-like organic semiconductor single crystals of an end-capped fluorene/phenylene co-oligomer provide low-threshold unidimensional stimulated emission. The Figure shows a similar to1.5 mm long crystals, and photograph of the gain-narrowed normalized emission spectra from a polycrystal (dotted line) a...
Data
Reversible holographic recording of surface-relief gratings in azo-dye polymers was recently evidenced using atomic force microscopy. Irradiation with an interference pattern between polarized laser beams was observed to lead to quantitative mass-transport. The origin of such efficient photo-driven mass transport comes from chromophore migration fr...