30 research outputs found
Pump-Enhanced Continuous-Wave Magnetometry using Nitrogen-Vacancy Ensembles
Ensembles of nitrogen-vacancy centers in diamond are a highly promising
platform for high-sensitivity magnetometry, whose efficacy is often based on
efficiently generating and monitoring magnetic-field dependent infrared
fluorescence. Here we report on an increased sensing efficiency with the use of
a 532-nm resonant confocal cavity and a microwave resonator antenna for
measuring the local magnetic noise density using the intrinsic nitrogen-vacancy
concentration of a chemical-vapor deposited single-crystal diamond. We measure
a near-shot-noise-limited magnetic noise floor of 200 pT/
spanning a bandwidth up to 159 Hz, and an extracted sensitivity of
approximately 3 nT/, with further enhancement limited by the
noise floor of the lock-in amplifier and the laser damage threshold of the
optical components. Exploration of the microwave and optical pump-rate
parameter space demonstrates a linewidth-narrowing regime reached by virtue of
using the optical cavity, allowing an enhanced sensitivity to be achieved,
despite an unoptimized collection efficiency of <2 %, and a low
nitrogen-vacancy concentration of about 0.2 ppb.Comment: 10 pages and 5 figure
A chemical survey of exoplanets with ARIEL
Thousands of exoplanets have now been discovered with a huge range of masses, sizes and orbits: from rocky Earth-like planets to large gas giants grazing the surface of their host star. However, the essential nature of these exoplanets remains largely mysterious: there is no known, discernible pattern linking the presence, size, or orbital parameters of a planet to the nature of its parent star. We have little idea whether the chemistry of a planet is linked to its formation environment, or whether the type of host star drives the physics and chemistry of the planetâs birth, and evolution. ARIEL was conceived to observe a large number (~1000) of transiting planets for statistical understanding, including gas giants, Neptunes, super-Earths and Earth-size planets around a range of host star types using transit spectroscopy in the 1.25â7.8 ÎŒm spectral range and multiple narrow-band photometry in the optical. ARIEL will focus on warm and hot planets to take advantage of their well-mixed atmospheres which should show minimal condensation and sequestration of high-Z materials compared to their colder Solar System siblings. Said warm and hot atmospheres are expected to be more representative of the planetary bulk composition. Observations of these warm/hot exoplanets, and in particular of their elemental composition (especially C, O, N, S, Si), will allow the understanding of the early stages of planetary and atmospheric formation during the nebular phase and the following few million years. ARIEL will thus provide a representative picture of the chemical nature of the exoplanets and relate this directly to the type and chemical environment of the host star. ARIEL is designed as a dedicated survey mission for combined-light spectroscopy, capable of observing a large and well-defined planet sample within its 4-year mission lifetime. Transit, eclipse and phase-curve spectroscopy methods, whereby the signal from the star and planet are differentiated using knowledge of the planetary ephemerides, allow us to measure atmospheric signals from the planet at levels of 10â100 part per million (ppm) relative to the star and, given the bright nature of targets, also allows more sophisticated techniques, such as eclipse mapping, to give a deeper insight into the nature of the atmosphere. These types of observations require a stable payload and satellite platform with broad, instantaneous wavelength coverage to detect many molecular species, probe the thermal structure, identify clouds and monitor the stellar activity. The wavelength range proposed covers all the expected major atmospheric gases from e.g. H2O, CO2, CH4 NH3, HCN, H2S through to the more exotic metallic compounds, such as TiO, VO, and condensed species. Simulations of ARIEL performance in conducting exoplanet surveys have been performed â using conservative estimates of mission performance and a full model of all significant noise sources in the measurement â using a list of potential ARIEL targets that incorporates the latest available exoplanet statistics. The conclusion at the end of the Phase A study, is that ARIEL â in line with the stated mission objectives â will be able to observe about 1000 exoplanets depending on the details of the adopted survey strategy, thus confirming the feasibility of the main science objectives.Peer reviewedFinal Published versio
Quadrature measurements of a bright squeezed state via sideband swapping
The measurement of an arbitrary quadrature of a bright quantum state of light is a commonly requested action in many quantum information protocols, but it is experimentally challenging with previously proposed schemes. We suggest that the quadrature be measured at a specific sideband frequency of a bright quantum state by transferring the sideband modes under interrogation to a vacuum state and subsequently measuring the quadrature via homodyne detection. The scheme is implemented experimentally, and it is successfully tested with a bright squeezed state of light. (C) 2009 Optical Society of Americ
Tuotekehitysprosessin kehittÀminen toimintatavaksi valmistalotehtaassa, Case: Kilpailukykyinen tilaelementtitalo
Tutkimuksen tarkoituksena oli seurata tuotekehitysprojektia Finndomon SÀynÀtsalon tehtaalla.
Tavoitteena oli saada esille tuotekehittÀmisen nykyiset ongelmat ja kehittÀÀ tuotekehitysprosessia toimintatavaksi.
Tutkimus tehtiin osallistumalla aktiivisesti yhteen tuotekehitysprojektiin ja haastattelemalla yrityksen työntekijöitÀ.
Projektin taustatiedoiksi selvitettiin eri elementtijÀrjestelmÀt ja taloteollisuuden keskeiset tuotekehityskohteet.
KehitettÀvÀn tuotteen kohdesegmentin mÀÀrittÀmiseksi haettiin tietoa valmistalomarkkinoista ja kilpailijayrityksistÀ Suomessa.
TuotekehittÀmisprosessin arviointia varten tutkimuksessa tehtiin teemahaastatteluita.
Haastattelujen tarkoituksena oli saada selville, mitÀ uusia asioita ja vaikeuksia yritys kohtaa pyrkiessÀÀn uuteen tavoitesegmenttiin, ja mitÀ parannettavaa nykyisessÀ tuotekehitysprosessissa on.
Tutkimuksen tuloksena oli rÀÀtÀlöity malli tuotekehittÀmisestÀ ja prosessikuva.
Mallin tÀrkeimpÀnÀ muutoksena oli yhteinen tavoitteiden mÀÀrittÀminen tuotekehitysprojektille ja projektien vÀlinen vuorovaikutus.
TuotekehittÀminen ei saa olla liian tuotantolÀhtöistÀ, mutta liika tuotteiden asiakaskohtainen rÀÀtÀlöinti ja yksityiskohtainen muuntelu ei myöskÀÀn ole yritykselle kannattavaa.
Projektin onnistumisen kannalta on tÀrkeÀÀ tunnistaa markkinatilanne ja yrityksen oma strategia.
KehitettÀvÀlle tuotteelle on löydyttÀvÀ markkinat projektin jÀlkeen.
Yrityksen eri osastot ovat riippuvaisia toisistaan, jolloin yhdelle osastolle mÀÀritetyt tavoitteet voivat aiheuttaa muutosvaatimusta myös muiden osastojen toimintatapoihin.
Tuotekehitysprojektin seuraamisessa esille tuli puutteita projektien hallinnassa ja aikataulussa.
Projektiin on pyrittÀvÀ saamaan projektin kannalta tÀrkeimmÀt avainhenkilöt toimimaan aktiivisessa vuorovaikutuksessa.
TuotekehittÀmistÀ rajaavat työntekijÀresurssit ja budjetti.
TÀrkeimmÀt tavat parantaa tuotekehitysprosessia oli tiivistÀÀ tehtaiden vÀlistÀ yhteistyötÀ, selkeyttÀ projektien tavoitetta ja priorisoida tÀrkeimpiÀ projekteja.
Aikaisemmissa projekteissa tulosten raportointi oli puutteellista.
Henkilöstön kouluttaminen nÀhtiin myös tÀrkeÀnÀ