Search results for "microcavities"
showing 8 items of 8 documents
AlInN based Microcavities
2006
Room temperature polariton luminescence from a GaN∕AlGaN quantum well microcavity
2006
The authors report on the demonstration of strong light-matter coupling at room temperature using a crack-free UV microcavity containing GaN/AlGaN quantum wells (QWs). Lattice-matched AlInN/AlGaN distributed Bragg reflectors (DBRs) with a maximum peak reflectivity of 99.5% and SiO2/Si3N4 DBRs were used to form high finesse hybrid microcavities. State-of-the-art GaN/Al0.2Ga0.8N QWs emitting at 3.62 eV with a linewidth of 45 meV at 300 K were inserted in these structures. For a 3 lambda/2 microcavity containing six QWs, the interaction between cavity photons and QW excitons is sufficiently large to reach the strong coupling regime. A polariton luminescence is observed with a vacuum field Rabi…
Ultrahigh-Q Tunable Whispering-Gallery-Mode Microresonator
2009
Typical microresonators exhibit a large frequency spacing between resonances and a limited tunability. This impedes their use in a large class of applications which require a resonance of the microcavity to coincide with a predetermined frequency. Here, we experimentally overcome this limitation with highly prolate-shaped whispering-gallery-mode "bottle microresonators" fabricated from standard optical glass fibers. Our resonators combine an ultra-high quality factor of 360 million, a small mode volume, and near lossless fibre coupling, characteristic of whispering-gallery-mode resonators, with a simple and customizable mode structure enabling full tunability.
Blue lasing at room temperature in high quality factor GaN/AlInN microdisks with InGaN quantum wells
2007
The authors report on the achievement of optically pumped III-V nitride blue microdisk lasers operating at room temperature. Controlled wet chemical etching of an AlInN interlayer lattice matched to GaN allows forming inverted cone pedestals. Whispering gallery modes are observed in the photoluminescence spectra of InGaN/GaN quantum wells embedded in the GaN microdisks. Typical quality factors of several thousands are found (Q>4000). Laser action at similar to 420 nm is achieved under pulsed excitation at room temperature for a peak power density of 400 kW/cm(2). The lasing emission linewidth is down to 0.033 nm.
Room-temperature polariton luminescence from a bulk GaN microcavity
2006
We report strong exciton-photon coupling at room temperature in a hybrid high quality bulk 3 lambda/2 GaN cavity with a bottom lattice-matched AlInN/AlGaN distributed Bragg reflector through angle-resolved polarized photoluminescence (PL). Coupling of the optically active free excitons (X-A, X-B, and X-C) to the cavity mode is demonstrated, with their contribution to the PL spectra varying with polarization. Under TE polarization, exciton oscillator strengths for X-A and X-B are about one order of magnitude larger than in bulk GaAs. Photoluminescence exhibits a strong bottleneck effect despite its thermal lineshape.
Bottle microresonator with actively stabilized evanescent coupling
2011
The evanescent coupling of light between a whispering-gallery-mode bottle microresonator and a sub-wavelength-diameter coupling fiber is actively stabilized by means of a Pound-Drever-Hall technique. We demonstrate the stabilization of a critically coupled resonator with a control bandwidth of 0.1 Hz, yielding a residual transmission of (9 \pm 3) \times 10^-3 for more than an hour. Simultaneously, the frequency of the resonator mode is actively stabilized.
Crystal growth and characterization of Zn1-xMgxO advanced micro- and nanostructures
2018
Dentro de la creciente área de investigación de la física de semiconductores, los pertenecientes a la familia II-VI se han convertido en un campo fundamental de la física de materiales debido a que sus propiedades fotofísicas son únicas para crear una nueva generación de dispositivos en el campo de la fotónica y la microelectrónica. Entre ellos, los semiconductores basados en ZnO han ganado un considerable interés en la comunidad científica en parte debido a su alta energía de enlace del excitón (60 meV) la cual es 2.4 veces más alta que la energía térmica a temperatura ambiente. Este hecho puede dar lugar a emisión laser excitónica a temperaturas incluso mayores que la ambiente. Además, gr…
Etude en champ proche et en champ lointain de composants périodiquement nanostructurés : cristaux photoniques et tamis à photons
2004
Recently, a new class of optical components is appeared. Its main characteristic is to be formed by a periodical sub-wavelength pattern, leading to the apparition of a spectral domain where propagation of light inside the structure is forbidden -- a photonic bandgap. This work is devoted to the study in the near- and far-field of two kinds of periodical optical components: photonic crystals (PCs) and nanostructured metallic films that exhibit the so-called enhanced transmission. First, we study two-dimensional PCs with a scanning near-field optical microscope (SNOM) in collection mode. With this SNOM, we directly map the intensity distribution inside PC-based microcavities. We also evidence…