Kevin Bourhis

Silver clusters embedded in glass as a perennial high capacity optical recording medium.

[∗] Dr. A. Royon , Dr. M. Bellec , G. Papon , Dr. B. Bousquet , Prof. L. Canioni Centre de Physique Moleculaire Optique et Hertzienne University of Bordeaux 351 Cours de la Liberation, 33405 Talence (France) E-mail: l.canioni@cpmoh.u-bordeaux1.fr K. Bourhis , Dr. T. Cardinal Institut de Chimie de la Matiere Condensee de Bordeaux University of Bordeaux 87 Avenue du Docteur Schweitzer, 33608 Pessac (France) Dr. Y. Deshayes Laboratoire de l ′ Integration du Materiau au Systeme University of Bordeaux 351 Cours de la Liberation, 33405 Talence (France)

Beat the diffraction limit in 3D direct laser writing in photosensitive glass

Three-dimensional (3D) femtosecond laser direct structuring in transparent materials is widely used for photonic applications. However, the structure size is limited by the optical diffraction. Here we report on a direct laser writing technique that produces subwavelength nanostructures independently of the experimental limiting factors. We demonstrate 3D nanostructures of arbitrary patterns with feature sizes down to 80 nm, less than one tenth of the laser processing wavelength. Its ease of implementation for novel nanostructuring, with its accompanying high precision will open new opportunities for the fabrication of nanostructures for plasmonic and photonic devices and for applications in metamaterials.

Three-dimensional direct femtosecond laser writing of second-order nonlinearities in glass

We demonstrate that direct femtosecond laser writing in silver-containing zinc and gallium phosphate glass enables generation of three-dimensional (3D) optical second-order nonlinear microstructures having an χ(2) value about 2.5 times that of quartz. The proposed physical model involves photo-reduction, photo-dissociation, and migration of silver species within the glass matrix. 3D laser-written second-order nonlinear structures could become a new class of nonlinear optical components.

Durability study of a fluorescent optical memory in glass studied by luminescence spectroscopy

Thermal stress at 100 °C for more than 3168 h of a fluorescent optical memory composed of laser written silver nano clusters embedded in glass has been performed. Measurements of luminescence spectra have been carried out at different times, showing a decreasing and an increasing evolution of the red and the blue part of the spectrum, respectively. This evolution has been attributed to the diffusion and the reorganization of different silver species inside the matrix, altering the internal electric field. Stark effect based modeling enables the degradation mode of the memory.

Direct Laser-Writing in a silver-zinc doped phosphate glass: Spatial discrimination of aggregates - Formation mechanism

We report on spatially and spectrally-resolved linear optical properties induced by Direct Laser Writing in a prepared silver-doped phosphate glass, opening interesting possibilities for elementary photonics bricks. The formation mechanism of optical structures is proposed.

Design of silver activated phosphate and borophosphate based glasses for multi-scale structured optical materials

Silver activated exotic phosphate and borophosphate glass composition allows fabricating, after thermal poling and/or laser structuring, multi-scale structured optical materials. The spatial distribution and the identification of the silver species is are of important for optical property tailoring.

Femtosecond direct laser writing of linear and nonlinear optical properties in photosensitive glass

Glasses specifically tailored with photosensitive agents such as silver are efficient material for direct laser writing localized linear and non linear optical properties. The relation between the photo-induced structures and the modifications of the linear and optical properties are discussed.

Direct laser writing of nonlinear properties in photosensitive glass

A 1030 nm pulsed femtosecond laser has been use to induce modifications in silver containing glass namely femto-photo luminescent glass (FPL) and Photo-thermo refractive glass (PTR). The 5W 10Mhz laser is focused at a depth of 200 μm in the glass using a 0,52 NA objective. The output polarization of the laser is TM. The tailoring of the number of pulses, pulse energy and repetition rate is achieve by acousto-optic filtering. The interaction resulted in the creation of stable pipe-shaped silver clusters forming bellow refraction-limit 3D structures. Those nano-structures exhibit non-linear properties such as SHG and THG as well as fluorescence. Due to multiphoton absorption, free electrons are created in the central part of the beam, enabling the reduction of Ag+ silver ions into Ag0 and subsequently AgmX+. The cumulated thermal effect of the pulses weakens the glass matrix allowing the diffusion of the AgmX+. The ion concentration gradient creates a buried electric field enabling non-linear properties. Influences of polarization, dose and fluence on the nonlinear properties are investigated. Our explanation of the causes of SHG and THG are validated by the accordance between the theory and the measurement. Comparisons between theoretic model and our results showing accordance in the limits of out 2D model are demonstrated using different incoming polarizations.

Development of Photosensitive Glasses for Direct Laser Writing

Luminescent silver clusters can be locally formed thanks to multi-photon absorption using high repetition rate femtosecond laser. The optical properties are strongly related to the glass composition and structure.

Second harmonic generation by electro-poling in femtosecond laser induced micro-structured silver containing glass

Laser structuring and electro-poling has been carried out in silver containing glasses. The second-order NLO response after direct laser patterning has been investigated in the scope of developing further practical use of the material.