4 research outputs found
Efficient optical coupling to gallium arsenide nano-waveguides and resonators with etched conical fibers
We explore new methods for coupling light to on-chip gallium arsenide
nanophotonic structures using etched conical optical fibers. With a
single-sided conical fiber taper, we demonstrate efficient coupling to an
on-chip photonic bus waveguide in a liquid environment. We then show that it is
possible to replace such on-chip bus waveguide by two joined conical fibers in
order to directly couple light into a target whispering gallery disk resonator.
This latter approach proves compliant with demanding environments, such as a
vibrating pulse tube cryostat operating at low temperature, and it is
demonstrated both in the telecom band and in the near infrared close to 900 nm
of wavelength. The versatility, stability, and high coupling efficiency of this
method are promising for quantum optics and sensing experiments in constrained
environments, where obtaining high signal-to-noise ratio remains a challenge
Experimental teaching -A tribute to Yves Couder by the example: stroboscopy and fluorescence lifetime with a fan
International audienceYves Couder created âPhyExpâ at Paris Diderot University in 80s. This undergraduate course was meant to introduce experimental physics to students through projects. This approach proved fruitful both for students and teachers and has been replicated Ecole SupĂ©rieure de Physique et Chimie Industrielles (ESPCI). As a tribute to Yves, we report here the results obtained during this course about a specific project, namely the measurement of fluorescence lifetimes using stroboscopy and a fan. We obtain quantitative measurements for both Europium and Terbium that are commonly used in fluorescent tubes and we further study the variation of the lifetime with temperature.Durant les annĂ©es 80, Yves Couder a introduit une nouvelle mĂ©thode dâenseignement Ă lâUniversitĂ© Paris Diderot Ă travers le module âPhyExpâ. Au cours de projets expĂ©rimentaux, les Ă©tudiants dĂ©couvraient des problĂšmes originaux de physique ainsi que les mĂ©thodes permettant dây apporter des solutions. Ce module a Ă©tĂ© reproduit Ă lâEcole SupĂ©rieure de Physique et Chimie Industrielles (ESPCI) depuis 2014. En forme dâhommage Ă lâapproche dâYves Couder, nous pĂ©sentons ici les rĂ©sultats obtenus par un groupe dâĂ©tudiants dont le projet consistait Ă mesurer des temps de vie de fluorescence avec des moyens limitĂ©s (un ventilateur et un spectromĂštre). En utilisant une mĂ©thode stroboscopique, nous avons pu obtenir des mesures quantitatives pour les raies visibles de lâEuropium et du Terbium, deux Ă©lĂ©ments prĂ©sents dans les tubes fluorescents. Nous avons Ă©galement Ă©valuĂ© la variation de ces temps de vie avec la tempĂ©rature