Flat lenses allow the integration of additional components in complex systems without making them bulky. Large-scale flat lenses may be designed from the optimisation of metalenses elements and their arrangement at a macroscopic scale. Diffractive lenses are excellent candidates for tests on the optimisation algorithm. We design and fabricate large-scale achromatic diffractive lenses which are combined with sensors for the diagnosis of ophthalmic diseases.

This report presents an unprecedented back-end method for biofunctionalizing a large-scale array of nanocantilevers. The method presented here relies on the use of a modified nanocontact printing (nCP) process where antibodies are delivered onto a chip containing up to 106 nanostructures/cm2 from the high-parts (grooves) of a polymer stamp while its base sits on the nanocantilevers' chip, thus providing mechanical stability. The presence of antibodies is validated by fluorescent microscopy and measurement of the nanocantilever resonance frequency shifts provoked by the added biological mass demonstrates that the cantilevers retain their mechanical integrity.

In this paper, we present a back-end method for biofunctionalizing a large-scale array of nanocantilevers. Our method relies on the use of a modified microcontact printing process where molecules are delivered onto the fragile structures from the grooves of the stamp while its base sits on the chip, thus providing mechanical stability. We have used this method to print antibodies onto fabricated chips containing up to 105 nanostructures/cm2and the presence of antibodies was validated by fluorescent microscopy. Furthermore, measurement of the nanocantilever resonant frequency shifts provoked by a mean added mass of ∼140fg/cantilever demonstrated that the cantilevers retained their mechanical integrity. Hence, the method presented here aims at providing an answer to the biofunctionalization of freestanding nanostructures for their use as biosensors.

We use liquid-gas microfluidics as a low cost, tunable microstructuring tool, with envisioned applications to optics. We obtain stable self-organized bubble networks, with micrometric pitches. We use interfacial tension to engineer controlled geometrical defects, relevant for photonics, within these microfluidic photonic crystals.

Dans le domaine des microondes, l'optique represente une solution elegante pour la montee en facteur de qualite dans les systemes de generation de frequence. Differents types de resonateurs optiques nous permettent d'atteindre des facteurs de qualite au dela de 109 et sont utilises comme une alternative aux lignes a retard optiques utilisees dans les oscillateurs optoelectroniques (OEO) classiques. Les proprietes en termes de coefficient de qualite de boucles resonantes fibrees sont presentees et une application de l'utilisation de ces resonances pour la stabilisation d'oscillateurs microonde est detaillee. Les travaux concernent a la fois une etude theorique et une etude experimentale du dispositif, avec comme parametre principal l'etude de la stabilite de frequence de l'oscillateur et de la contribution du bruit blanc de frequence sur le bruit de phase de l'oscillateur. Une etude theorique et experimentale sur la stabilite thermique de l'oscillateur est aussi presentee.

This study concerns mainly the phase noise due to the white frequency noise induced by our resonators and is comparable to the one proposed for purely microwave oscillators.

In the microwave domain and among many other advantages, optics represents an elegant solution to increase the quality Q factor in a system. Different types of optical resonators lead to Q factors above 109, and these resonators can be used as an alternative to optical delay lines to set up the frequency in optoelectronic oscillators (OEO). However, microwave-optics is also a complex field, and if the use of optical resonators in high spectral purity frequency generation systems like OEO has been already demonstrated, many aspects of these OEOs are still incompletely understood, especially the contribution to the oscillator phase noise of the different optical and microwave elements used in the oscillator system. In order to improve the phase noise of a fiber ring resonator based OEO, this oscillator has been theoretically studied in term of white frequency noise. In this paper, we present a theoretical study that has lead us to optimize a fiber ring resonator and the experimental phase noise results obtained for an OEO based on an optimized optical resonator. The OEO thermal stability is also investigated in this paper.

Microwave optical systems for frequency generation are described in this paper. The goal is to reach high spectral purity in the microwave frequency range using ultra high Q optical resonators. The resonators investigated are of two types : resonant (passive) fiber rings and WGM tridimensional resonators. They all feature ultra high optical Q factors, in excess of 108 or 109 near 1550 nm. These resonators also sustain a large number of optical resonances, and the microwave signal is stabilized on two (or more) resonances of this optical comb. Different problems have to be overcome in order to reach a functional system, such as : resonator design and coupling, laser stabilization on a resonance, overall system design, noise optimization... This paper gives an overlook on these problems, and on some solutions we found to work towards a compact and efficient microwave opto-electronic oscillator (OEO). A first result is presented on a 10 GHz OEO based on a resonant fiber ring.

L'etude des nouveaux oscillateurs hyperfrequences bases sur les resonateurs optiques a tres forts facteurs de qualite necessite une comprehension approfondie de l'influence de ces resonateurs sur le bruit de phase. Nous presentons une etude theorique de l'influence du bruit blanc de frequence sur le bruit de phase de l'oscillateur et l'optimisation d'un resonateur optique.

Diffraction-limited sources around 976 nm are attractive to build sources around 488 nm, or to pump rare-earth-doped materials. Continuous wave efficient lasers have been obtained with single-mode fibres, in which we demonstrate pulsed laser diode amplification with gains higher than 30 dB. Theoretical studies can predict the amplifier performances versus the input signal characteristics and show the pulse width influence on excited state population. We used a classical timespace two-level model that we solved thanks to a Finite-Difference Time-Domain method. These simulations taking into account both time and space evolutions and a parasitic laser effect describe correctly the experimental results.

Nous presentons une etude theorique de la contribution du bruit de frequence blanc sur le bruit de phase d'un oscillateur optoelectronique base sur des resonateurs optiques. Cette etude nous permet d'optimiser nos resonateurs optiques a tres forts facteurs de qualite.

In order to improve the phase noise of high purity OEO based on optical resonators, like resonant fibre rings, these oscillators have been theoretically studied in terms of white frequency noise. We present here the optimization of the performances of a fibre ring resonator and the experimental phase noise results we obtained for the OEO based on an optimized very high quality factor optical resonator.

Les performances des resonateurs hyperfrequences en termes de facteurs de qualite sont actuellement limitees. Une solution consiste a transporter les hyperfrequences sur un support different, en l'occurrence une onde optique. Les resonateurs optiques deviennent alors des objets tres interessants pour l'elaboration de nouveaux resonateurs hyperfrequences plus performants. Des facteurs de qualite optiques superieurs a 109 peuvent etre atteints avec des resonateurs fibres ou a modes de galerie, par exemple, donnant ainsi acces a des facteurs de qualite superieurs a 105 a 20 GHz. Nous presentons donc notre etude de differents resonateurs optiques (resonateurs a modes de galerie et boucles de fibre) destines a la stabilisation d'oscillateurs hyperfrequences autour de 10 GHz, ainsi que leur application a la realisation d'un oscillateur opto-micro-onde a cette frequence.

New resonators are investigated in order to design compact and high performances microwave oscillators. Because of long wavelengths in microwave range, dimensions of resonators are intrinsically large. Secondly, the quality factor of these resonators is now limited to about 2.10 5 at 10 GHz with whispering gallery modes (WGM) sapphire resonators. Nevertheless, it is possible to solve these difficulties if we use optical waves as a carrier for the RF frequencies, for example a 1.5 µm-laser. Resonators become optical ones, with low dimensions due to short wavelengths. The optical resonator creates an optical frequency comb with microwave spacing. Each mode of this comb is characterized by an optical Q factor (Q opt ) and an equivalent RF Q factor (Q RF ). Q RF is the product of Q opt and the RF to optical frequencies ratio. At 1.55 µm, this frequency ratio is about 10 4 at 20GHz and Q opt must be at least equal to 10 8 to obtain a quality at 20 GHz better than the microwave resonators. We present different high-Q optical resonators and an application of one of them to microwave photonics oscillators.

A technique for the simulation of a microwave optical system is described. This technique, based on microwave CAD software, allows the simulation of the gain and noise performance. The optical devices are described using either an equivalent circuit approach or equation based models. The simulations of a simple RF optical link and of a more complex system, a microwave optical delay line frequency discriminator, are presented.

RESUME Le facteur de qualité des résonateurs hyperfréquences a actuellement atteint ses limites, notamment pour la montée en fréquence des oscillateurs hyperfréquences. Une solution consiste à transporter les hyperfréquences sur une onde optique et à élaborer des résonateurs optiques très performants. Pour cela, nous développons des anneaux de fibre résonants avec des facteurs de qualité optiques supérieurs à 109. Il est donc nécessaire de caractériser finement ces résonateurs. Différentes méthodes de détermination de leur facteur de qualité optique sont possibles, et nous présentons ici une comparaison entre les trois méthodes que nous utilisons. MOTS-CLEFS : Résonateurs optiques ; facteur de qualité ; caractérisation optique ; optique-micro-onde.

Le facteur de qualite des resonateurs hyperfrequences est actuellement limite. Une solution consiste a transporter les hyperfrequences sur une onde optique, et a effectuer le filtrage ou la reference de frequence dans le domaine optique. Des resonateurs optiques fibres ou a modes de galerie permettent d'atteindre des facteurs de qualite superieurs a 109, donnant ainsi acces a des facteurs de qualite equivalents superieurs a 105 pour le filtrage d'une modulation RF au voisinage de 20 GHz. Nous presentons donc une etude de differents resonateurs optiques destines a la stabilisation d'oscillateurs hyperfrequences, ainsi que leur application a la realisation d'un oscillateur opto-micro-onde a cette frequence.

Le facteur de qualite des resonateurs hyperfrequences a actuellement atteint ses limites, notamment pour la montee en frequence des oscillateurs hyperfrequences. Une solution consiste a transporter les hyperfrequences sur une onde optique et a elaborer des resonateurs optiques tres performants. Pour cela, nous developpons des anneaux de fibre resonants avec des facteurs de qualite optiques superieurs a 109. Il est donc necessaire de caracteriser finement ces resonateurs. Differentes methodes de determination de leur facteur de qualite optique sont possibles, et nous presentons ici une comparaison entre les trois methodes que nous utilisons.

Different high-Q optical resonators are presented in this communication. Our aim is to use them to develop compact high performances microwave oscillators. The optical quality factor of a quartz disk used as a whispering gallery modes resonator has been measured to be higher than 109. We also investigate the potentialities of high-Q fibre ring resonators. The performances of an optoelectronic oscillator at 10 GHz based on such a passive fibre ring resonator are presented here.