74 research outputs found
Confocal reflectance microscopy for determination of microbubble resonator thickness
Optical Micro Bubble Resonators (OMBR) are emerging as new type of sensors characterized by high Q-factor and embedded micro-fluidic. Sensitivity is related to cavity field penetration and, therefore, to the resonator thickness. At the state of the art, methods for OMBR's wall thickness evaluation rely only on a theoretical approach. The purpose of this study is to create a non-destructive method for measuring the shell thickness of a microbubble using reflectance confocal microscopy. The method was validated through measurements on etched capillaries with different thickness and finally it was applied on microbubble resonators
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
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
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
Protocole de fabrication par voie colloĂŻdalede cristaux photoniques 3D
session 7 " Cristaux photoniques "National audienceNous présentons ici les détails d'un processus sol-gel utilisé pour synthétiser des sphères de silice, en portant une attention particulière aux conditions expérimentales permettant de contrôler leur taille. Nous avons élaboré un protocole dans le but d'obtenir des microsphères avec une faible dispersion, et démontré que de larges domaines cristallins ordonnés d'opale synthétique montrant une " stop band " peuvent être produits en quelques jours par déposition verticale et sédimentation assistée par évaporation. La microscopie électronique à balayage a été employée pour caractériser les échantillons. Des mesures de réflexion et transmission ont été effectuées pour mettre en évidence la haute qualité des opales réalisées
microspherical laser of ytterbium-erbium codoped phosphate glass - coupling to an external cavity
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Microsphere Laser in Er3+/Yb3+ Co-doped Phosphate Glass: Coupling with an External Cavity
conference 5333 « Laser Resonators and Beam Control VII », session 5 « Microresonators and Photonic Crystals I » [5333-18]International audienceEr3+/Yb3+ co-doped phosphate glass microsphere lasers have been studied under pumping by a fiber taper at 1480 nm. Whispering Gallery Mode laser spectra were analyzed for different sphere diameters. The gain spectrum is calculated for the transition 4I13/2 → 4I15/2 around 1550 nm. Red-shift effect on the wavelengths of both fluorescence and laser spectra is experimentally observed when the pump power is increased, originating from thermal effects. We showed coupling effect between microspherical laser and an external cavity made by a metallic mirror. We observed line shift to lower wavelengths due to optical feedback effect
Laser microsphérique en verre phosphate co-dopé erbium ytterbium: couplage avec une cavité externe
COLOQ 8 - Huitième colloque sur les lasers et l'optique quantique ( Toulouse, France, septembre 2003)National audienceNous montrons l'effet du couplage entre un laser microsphérique et une cavité externe constituée d'un miroir métallique. Nous observons un effet de contre-réaction optique avec décalage vers de plus courtes longueurs d'ondes
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