Active and Quantum Integrated Photonic Elements by Ion Exchange in Glass

Ion exchange in glass has a long history as a simple and effective technology to produce gradient-index structures and has been largely exploited in industry and in research laboratories. In particular, ion-exchanged waveguide technology has served as an excellent platform for theoretical and experimental studies on integrated optical circuits, with successful applications in optical communications, optical processing and optical sensing. It should not be forgotten that the ion-exchange process can be exploited in crystalline materials, too, and several crucial devices, such as optical modulators and frequency doublers, have been fabricated by ion exchange in lithium niobate. Here, however, we are concerned only with glass material, and a brief review is presented of the main aspects of optical waveguides and passive and active integrated optical elements, as directional couplers, waveguide gratings, integrated optical amplifiers and lasers, all fabricated by ion exchange in glass. Then, some promising research activities on ion-exchanged glass integrated photonic devices, and in particular quantum devices (quantum circuits), are analyzed. An emerging type of passive and/or reconfigurable devices for quantum cryptography or even for specific quantum processing tasks are presently gaining an increasing interest in integrated photonics; accordingly, we propose their implementation by using ion-exchanged glass waveguides, also foreseeing their integration with ion-exchanged glass lasersThis research was funded by Xunta de Galicia, Consellería de Educación, Universidades e FP, Grant GRC Number ED431C2018/11S

Microspherical laser in Erbium-Ytterbium-doped glass

session A « Micro laser sources » [A3]International audienceWe present experimental results on a Er3+/Yb3+ doped microspherical laser. Our experiments have been focused on the 4I13/2 → 4I15/2 transition at 1550 nm of erbium ions in phosphate glass spheres. We also report on the effects that the interaction between the WGM modes of the glass sphere and an external metallic mirror has on the laser emission

High quality factor 1-D Er 3+ -activated dielectric microcavity fabricated by RF-sputtering

Rare earth-activated 1-D photonic crystals were fabricated by RF-sputtering technique. The cavity is constituted by an Er3+-doped SiO2 active layer inserted between two Bragg reflectors consisting of ten pairs of SiO2/TiO2 layers. Scanning electron microscopy is employed to put in evidence the quality of the sample, the homogeneities of the layers thickness and the good adhesion among them. Near infrared transmittance and variable angle reflectance spectra confirm the presence of a stop band from 1500 nm to 2000 nm with a cavity resonance centered at 1749 nm at 0° and a quality factor of 890. The influence of the cavity on the 4I13/2 -> 4I15/2 emission band of Er3+ ion is also demonstrated

Ag-sensitized Tb3+/Yb3+ codoped silica-zirconia glasses and glass-ceramics: Systematic and detailed investigation of the broadband energy-transfer and downconversion processes

Abstract Various studies report that Tb3+/Yb3+ co-doped materials can split one UV or 488 nm (visible) photon in two near infrared (NIR) photons at 980 nm by an energy-transfer process involving one Tb3+ and two Yb3+ ions. Additionally, it was demonstrated that Ag multimers can provide an efficient optical sensitizing effect for rare earth ions (RE3+ ions), resulting in a broadband enhanced excitation, which could have a significant technological impact, overcoming their limited spectral absorptions and small excitation cross sections. However, a systematic and detailed investigation of the down-conversion process enhanced by Ag nanoaggregates is still lacking, which is the focus of this paper. Specifically, a step by step analysis of the energy-transfer quantum-cutting chain in Ag-exchanged Tb3+/Yb3+ co-doped glasses and glass-ceramics is presented. Moreover, the direct Ag-Yb3+ energy-transfer is also considered. Results of structural, compositional, and optical characterizations are given, providing quantitative data for the efficient broadband Ag-sensitization of Tb3+/Yb3+ quantum cutting. A deeper understanding of the physical processes beneath the optical properties of the developed materials will allow a wiser realization of more efficient energy-related devices, such as spectral converters for silicon solar cells and light-emitting devices (LEDs) in the visible and NIR spectral regions

Planar coupling to high-Q lithium niobate disk resonators

We demonstrate optical coupling to high-Q lithium niobate disks from an integrated lithium niobate waveguide. The waveguides are made by proton exchange in X-cut lithium niobate substrate. The disks with diameter of 4.7 mm and thickness of 1 mm are made from commercial Z-cut lithium niobate wafers by polishing the edges into a spheroidal profile. Both resonance linewidth and cavity ringdown measurements were performed to calculate the Q factor of the resonator, which is in excess of 10(8). Planar coupling represents the most promising technique for practical applications of whispering gallery mode resonators

SnO2 based glasses : A viable photonic system

The present work focuses on sol-gel derived SnO2-based thin glass-ceramic films doped with Er3+ ions, fabricated by dipcoating technique. Our goal is to find a viable fabrication protocol to obtain them. Thin films with a variety of composition were synthesized and their structural, optical and spectroscopic properties were investigated. The FTIR spectra and X-ray diffraction patterns were used to characterize the structure of the thin films. The transparency of the thin film was tested by UV-Vis transmittance measurements. The energy transfer dynamic was investigated by time-resolved spectroscopy and photoluminescence measurements

A new system for animal products traceability and authentication: use of DNA analysis of natural tracers and example of application to dry cured hams

AbstractA few DNA based approaches have been developed to trace animal products from the farm to the consumer "fork". These approaches make use of the animal DNA that can be recovered during all steps of the production chain directly as part of the products that are obtained from them. This direct link between the animals and the products can be assessed using DNA markers like, for example, single nucleotide polymorphisms and microsatellites, for individual or population based (breed) traceability systems. However, these methods, in general, rely on the possibility to constitute banks of animal biological samples for critical/important steps of the production chain and analyse a large number of samples (individual traceability) or to identify breed/population multilocus informative markers or few specific mutations that can distinguish the breed/population of origin (breed traceability). Here we developed a new traceability and authentication system that makes use of the DNA contained in an added material..

About the role of phase matching between a coated microsphere and a tapered fiber: experimental study

nombre de pages 10International audienceCoatings of spherical optical microresonators are widely employed for different applications. Here the effect of the thickness of a homogeneous coating layer on the coupling of light from a tapered fiber to a coated microsphere has been studied. Spherical silica microresonators were coated using a 70SiO2 - 30HfO2 glass doped with 0.3 mol% Er3+ ions. The coupling of a 1480 nm pump laser inside the sphere has been assessed using a tapered optical fiber and observing the 1530-1580 nm Er3+ emission outcoupled to the same tapered fiber. The measurements were done for different coating thicknesses and compared with theoretical calculations to understand the relationship of the detected signal with the whispering gallery mode electric field profiles

Fabrication and characterization of Er+3 doped SiO2/SnO2 glass-ceramic thin films for planar waveguide applications

Glass-ceramics are a kind of two-phase materials constituted by nanocrystals embedded in a glass matrix and the respective volume fractions of crystalline and amorphous phase determine the properties of the glass-ceramics. Among these properties transparency is crucial in particular when confined structures, such as, dielectric optical waveguides, are considered. Moreover, the segregation of dopant rare-earth ions, like erbium, in low phonon energy crystalline medium makes these structures more promising in the development of waveguide amplifiers. Here we are proposing a new class of low phonon energy tin oxide semiconductor medium doped silicate based planar waveguides. Er3+ doped (100-x) SiO2- xSnO2 (x= 10, 20, 25 and 30mol%), glass-ceramic planar waveguide thin films were fabricated by a simple sol-gel processing and dip coating technique. XRD and HRTEM studies indicates the glass-ceramic phase of the film and the dispersion of ~4nm diameter of tin oxide nanocrystals in the amorphous phase of silica. The spectroscopic assessment indicates the distribution of the dopant erbium ions in the crystalline medium of tin oxide. The observed low losses, 0.5±0.2 dB/cm, at 1.54 ?m communication wavelength makes them a quite promising material for the development of high gain integrated optical amplifiers