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Lauri Halonen - One of the best experts on this subject based on the ideXlab platform.
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double resonant Absorption Measurement of acetylene symmetric vibrational states probed with cavity ring down spectroscopy
arXiv: Chemical Physics, 2016Co-Authors: Juho Karhu, J Nauta, Markku Vainio, Markus Metsala, Steven Hoekstra, Lauri HalonenAbstract:A novel mid-infrared/near-infrared double resonant Absorption setup for studying infrared-inactive vibrational states is presented. A strong vibrational transition in the mid-infrared region is excited using an idler beam from a singly resonant continuous-wave optical parametric oscillator, to populate an intermediate vibrational state. High output power of the optical parametric oscillator and the strength of the mid-infrared transition result in efficient population transfer to the intermediate state, which allows measuring secondary transitions from this state with a high signal-to-noise ratio. A secondary, near-infrared transition from the intermediate state is probed using cavity ring down spectroscopy, which provides high sensitivity in this wavelength region. Due to the narrow linewidths of the excitation sources, the rovibrational lines of the secondary transition are measured with sub-Doppler resolution. The setup is used to access a previously unreported symmetric vibrational state of acetylene, $\nu_1+\nu_2+\nu_3+\nu_4^1+\nu_5^{-1}$ in the normal mode notation. Single-photon transitions to this state from the vibrational ground state are forbidden. Ten lines of the newly measured state are observed and fitted with the linear least-squares method to extract the band parameters. The vibrational term value was measured to be at 9775.0018(45) $\text{cm}^{-1}$, the rotational parameter $B$ was 1.162222 $\text{cm}^{-1}$, and the quartic centrifugal distortion parameter $D$ was 3.998(62)$\times 10^{-6} \text{cm}^{-1}$, where the numbers in the parenthesis are one-standard errors in the least significant digits.
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double resonant Absorption Measurement of acetylene symmetric vibrational states probed with cavity ring down spectroscopy
Journal of Chemical Physics, 2016Co-Authors: Juho Karhu, J Nauta, Markku Vainio, Markus Metsala, Steven Hoekstra, Lauri HalonenAbstract:A novel mid-infrared/near-infrared double resonant Absorption setup for studying infrared-inactive vibrational states is presented. A strong vibrational transition in the mid-infrared region is excited using an idler beam from a singly resonant continuous-wave optical parametric oscillator, to populate an intermediate vibrational state. High output power of the optical parametric oscillator and the strength of the mid-infrared transition result in efficient population transfer to the intermediate state, which allows measuring secondary transitions from this state with a high signal-to-noise ratio. A secondary, near-infrared transition from the intermediate state is probed using cavity ring-down spectroscopy, which provides high sensitivity in this wavelength region. Due to the narrow linewidths of the excitation sources, the rovibrational lines of the secondary transition are measured with sub-Doppler resolution. The setup is used to access a previously unreported symmetric vibrational state of acetylene,...
Juho Karhu - One of the best experts on this subject based on the ideXlab platform.
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double resonant Absorption Measurement of acetylene symmetric vibrational states probed with cavity ring down spectroscopy
arXiv: Chemical Physics, 2016Co-Authors: Juho Karhu, J Nauta, Markku Vainio, Markus Metsala, Steven Hoekstra, Lauri HalonenAbstract:A novel mid-infrared/near-infrared double resonant Absorption setup for studying infrared-inactive vibrational states is presented. A strong vibrational transition in the mid-infrared region is excited using an idler beam from a singly resonant continuous-wave optical parametric oscillator, to populate an intermediate vibrational state. High output power of the optical parametric oscillator and the strength of the mid-infrared transition result in efficient population transfer to the intermediate state, which allows measuring secondary transitions from this state with a high signal-to-noise ratio. A secondary, near-infrared transition from the intermediate state is probed using cavity ring down spectroscopy, which provides high sensitivity in this wavelength region. Due to the narrow linewidths of the excitation sources, the rovibrational lines of the secondary transition are measured with sub-Doppler resolution. The setup is used to access a previously unreported symmetric vibrational state of acetylene, $\nu_1+\nu_2+\nu_3+\nu_4^1+\nu_5^{-1}$ in the normal mode notation. Single-photon transitions to this state from the vibrational ground state are forbidden. Ten lines of the newly measured state are observed and fitted with the linear least-squares method to extract the band parameters. The vibrational term value was measured to be at 9775.0018(45) $\text{cm}^{-1}$, the rotational parameter $B$ was 1.162222 $\text{cm}^{-1}$, and the quartic centrifugal distortion parameter $D$ was 3.998(62)$\times 10^{-6} \text{cm}^{-1}$, where the numbers in the parenthesis are one-standard errors in the least significant digits.
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double resonant Absorption Measurement of acetylene symmetric vibrational states probed with cavity ring down spectroscopy
Journal of Chemical Physics, 2016Co-Authors: Juho Karhu, J Nauta, Markku Vainio, Markus Metsala, Steven Hoekstra, Lauri HalonenAbstract:A novel mid-infrared/near-infrared double resonant Absorption setup for studying infrared-inactive vibrational states is presented. A strong vibrational transition in the mid-infrared region is excited using an idler beam from a singly resonant continuous-wave optical parametric oscillator, to populate an intermediate vibrational state. High output power of the optical parametric oscillator and the strength of the mid-infrared transition result in efficient population transfer to the intermediate state, which allows measuring secondary transitions from this state with a high signal-to-noise ratio. A secondary, near-infrared transition from the intermediate state is probed using cavity ring-down spectroscopy, which provides high sensitivity in this wavelength region. Due to the narrow linewidths of the excitation sources, the rovibrational lines of the secondary transition are measured with sub-Doppler resolution. The setup is used to access a previously unreported symmetric vibrational state of acetylene,...
N F Andreev - One of the best experts on this subject based on the ideXlab platform.
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high sensitive Absorption Measurement in ultrapure quartz glasses and crystals using time resolved photothermal common pass interferometry and its possible prospects
Journal of Applied Physics, 2021Co-Authors: K V Vlasova, A I Makarov, N F AndreevAbstract:We describe the functional capabilities of the time-resolved photothermal common-pass interferometry method. For two thermo-optical effect-based methods, photothermal common-pass interferometry and time-resolved photothermal common-pass interferometry, the achieved detection limit for Absorption Measurements in ultrapure quartz glasses (5 × 10−7 cm−1 and 2 × 10−9 cm−1, respectively) is given. The problem of calculating the variation of the refractive index tensor under local heating trigonal-symmetric crystals of class 32 by a focused laser beam is considered. For these crystals, it is shown that the problem of the influence of deformations on the measured signal is reduced to determine a thermo-optical parameter (an analog of dn/dT). The calculation of this parameter does not require a complete solution to the strain problem when the crystals are heated locally by laser radiation. The formulas for calculating the thermo-optical parameter P and its numerical values are presented. They are required to calibrate Absorption Measurements in crystalline quartz using the time-resolved photothermal common-pass interferometry scheme. For a full understanding, formulas of the theory of equilibrium deformations used in this study are presented. An analysis of the relevance of improving the thermo-optical method sensitivity for concentration Measurements of pollutant inclusions in crystals, ultrapure quartz glasses, and ambient air is presented.
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high sensitive Absorption Measurement in transparent isotropic dielectrics with time resolved photothermal common path interferometry
Applied Optics, 2018Co-Authors: K V Vlasova, A I Makarov, N F Andreev, Yu A KonstantinovAbstract:We propose a time-resolved photothermal common-path interferometry scheme at fast heating in the absence of heat diffusion and employ it to measure Absorption in Suprasil 311 silica glass (2.8·10-6 cm-1) at a wavelength of 1071 nm and continual Absorption in laboratory air (2.9·10-8 cm-1) for a signal-to-noise ratio of 100/1. The Absorption was measured at a thermally induced phase incursion of less than 0.1 rad in a heating beam, which guaranteed correct calibration. To calibrate this scheme, we developed a theory of diffraction on deformations taking into account the stresses arising in an inhomogeneous temperature field. This allowed us to use a standard glass K8 for calibration. The low level of noise and time resolution of pulsed signals allowed the distinguishing of the contributions of Kerr and striction nonlinearities to Absorption Measurements in Suprasil 311 silica glass and enabled the observance of the time evolution of strictional deformations. Additionally, an anomalous temporal development of the Absorption of broadband laser radiation in atmospheric air at 2.9·10-8 cm-1 has been revealed.
Jonathan C F Matthews - One of the best experts on this subject based on the ideXlab platform.
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Demonstrating an absolute quantum advantage in direct Absorption Measurement
Scientific Reports, 2017Co-Authors: Paulantoine Moreau, Rebecca Whittaker, Siddarth Koduru Joshi, Patrick M Birchall, Alex Mcmillan, John Rarity, Javier Sabines-chesterking, Jonathan C F MatthewsAbstract:Engineering apparatus that harness quantum theory promises to offer practical advantages over current technology. A fundamentally more powerful prospect is that such quantum technologies could out-perform any future iteration of their classical counterparts, no matter how well the attributes of those classical strategies can be improved. Here, for optical direct Absorption Measurement, we experimentally demonstrate such an instance of an absolute advantage per photon probe that is exposed to the absorbative sample. We use correlated intensity Measurements of spontaneous parametric downconversion using a commercially available air-cooled CCD, a new estimator for data analysis and a high heralding efficiency photon-pair source. We show this enables improvement in the precision of Measurement, per photon probe, beyond what is achievable with an ideal coherent state (a perfect laser) detected with 100% efficient and noiseless detection. We see this absolute improvement for up to 50% Absorption, with a maximum observed factor of improvement of 1.46. This equates to around 32% reduction in the total number of photons traversing an optical sample, compared to any future direct optical Absorption Measurement using classical light.
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demonstrating an absolute quantum advantage in direct Absorption Measurement
arXiv: Quantum Physics, 2016Co-Authors: Paulantoine Moreau, Javier Sabineschesterking, Rebecca Whittaker, Siddarth Koduru Joshi, Patrick M Birchall, Alex Mcmillan, John Rarity, Jonathan C F MatthewsAbstract:Engineering apparatus that harness quantum theory offers practical advantages over current technology. A fundamentally more powerful prospect is the long-standing prediction that such quantum technologies could out-perform any future iteration of their classical counterparts, no matter how well the attributes of those classical strategies can be improved. Here, we experimentally demonstrate such an instance of \textit{absolute} advantage per photon probe in the precision of optical direct Absorption Measurement. We use correlated intensity Measurements of spontaneous parametric downconversion using a commercially available air-cooled CCD, a new estimator for data analysis and a high heralding efficiency photon-pair source. We show this enables improvement in the precision of Measurement, per photon probe, beyond what is achievable with an ideal coherent state (a perfect laser) detected with $100\%$ efficient and noiseless detection. We see this absolute improvement for up to $50\%$ Absorption, with a maximum observed factor of improvement of 1.46. This equates to around $32\%$ reduction in the total number of photons traversing an optical sample, compared to any future direct optical Absorption Measurement using classical light.
Andreas Petzold - One of the best experts on this subject based on the ideXlab platform.
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minimizing light Absorption Measurement artifacts of the aethalometer evaluation of five correction algorithms
Atmospheric Measurement Techniques, 2009Co-Authors: Collaud M Coen, E Weingartner, Arnoud Apituley, Darius Ceburnis, R Fierzschmidhauser, H Flentje, J S Henzing, S G Jennings, M M Moerman, Andreas PetzoldAbstract:Obtaining a good description of aerosol optical properties for a physically and chemically complex evolving aerosol is computationally very expensive at present. The goal of this work is to propose a new numerical module computing the optical properties for 5 complex aerosol particles at low numerical cost so that it can be implemented in atmospheric models. This method aims to compute the optical properties online as a function of a given complex refractive index deduced from the aerosol chemical composition and the size parameters corresponding to the particles. The construction of look-up tables from the imaginary and the real part of the com10 plex refractive index and size parameters will also be explained. This approach is validated for observations acquired during the EUCAARI campaign on the Cabauw tower during May 2008 and its computing cost is also estimated. These comparisons show that the module manages to reproduce the scattering and absorbing behaviour of the aerosol during most of the fifteen-day period of observation 15 with a very cheap computationally cost.
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The Reno Aerosol Optics Study: An Evaluation of Aerosol Absorption Measurement Methods
Aerosol Science and Technology, 2005Co-Authors: Patrick J. Sheridan, Hans Moosmüller, W. Patrick Arnott, David S. Covert, John A. Ogren, Elisabeth Andrews, Dean B. Atkinson, Andreas Petzold, Beat Schmid, Anthony W. StrawaAbstract:The Reno Aerosol Optics Study (RAOS) was designed and conducted to compare the performance of many existing and new instruments for the in situ Measurement of aerosol optical properties with a focus on the determination of aerosol light Absorption. For this study, simple test aerosols of black and white particles were generated and combined in external mixtures under low relative humidity conditions and delivered to each Measurement system. The aerosol mixing and delivery system was constantly monitored using particle counters and nephelometers to ensure that the same aerosol number concentration and amount reached the different instruments. The aerosol light-scattering Measurements of four different nephelometers were compared, while the Measurements of seven light-Absorption instruments (5 filter based, 2 photoacoustic) were evaluated. Four methods for determining the aerosol light-extinction coefficient (3 cavity ring-down instruments and 1 folded-path optical extinction cell) were also included in the...