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David A. Ritchie - One of the best experts on this subject based on the ideXlab platform.
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high resolution gas phase spectroscopy with a distributed feedback terahertz quantum cascade laser
Applied Physics Letters, 2006Co-Authors: Heinz-wilhelm Hübers, Alexey Semenov, Lukas Mahler, Alessandro Tredicucci, Harvey E. Beere, Heiko Richter, S G Pavlov, David A. RitchieAbstract:The quantum cascade laser is a powerful, narrow linewidth, and continuous wave source of terahertz radiation. The authors have implemented a distributed feedback device in a spectrometer for high-resolution gas phase spectroscopy. Amplitude as well as frequency modulation schemes have been realized. The absolute frequency was determined by mixing the radiation from the quantum cascade laser with that from a gas laser. The Pressure Broadening and the Pressure shift of a rotational transition of methanol at 2.519THz were measured in order to demonstrate the performance of the spectrometer.The quantum cascade laser is a powerful, narrow linewidth, and continuous wave source of terahertz radiation. The authors have implemented a distributed feedback device in a spectrometer for high-resolution gas phase spectroscopy. Amplitude as well as frequency modulation schemes have been realized. The absolute frequency was determined by mixing the radiation from the quantum cascade laser with that from a gas laser. The Pressure Broadening and the Pressure shift of a rotational transition of methanol at 2.519THz were measured in order to demonstrate the performance of the spectrometer.
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high resolution gas phase spectroscopy with a distributed feedback terahertz quantum cascade laser
Applied Physics Letters, 2006Co-Authors: Heinz-wilhelm Hübers, Alexey Semenov, Lukas Mahler, Alessandro Tredicucci, Harvey E. Beere, Heiko Richter, S G Pavlov, David A. RitchieAbstract:The quantum cascade laser is a powerful, narrow linewidth, and continuous wave source of terahertz radiation. The authors have implemented a distributed feedback device in a spectrometer for high-resolution gas phase spectroscopy. Amplitude as well as frequency modulation schemes have been realized. The absolute frequency was determined by mixing the radiation from the quantum cascade laser with that from a gas laser. The Pressure Broadening and the Pressure shift of a rotational transition of methanol at 2.519THz were measured in order to demonstrate the performance of the spectrometer.
Volker Ebert - One of the best experts on this subject based on the ideXlab platform.
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Measurements of N2, CO2, Ar, O2 and Air Pressure Broadening Coefficients of the HCl P(5) Line in the 1–0 Band Using an Interband Cascade Laser
'MDPI AG', 2021Co-Authors: Javis A. Nwaboh, Olav Werhahn, Volker EbertAbstract:We determine the CO2, N2, Ar, O2 and air Pressure Broadening coefficients of the H35Cl P(5) absorption line at 2775.77 cm−1 in the fundamental (1←0) band using a newly developed direct tunable diode laser absorption spectroscopy (dTDLAS)-based spectrometer employing a mid-IR interband cascade laser (ICL). For the first time, a reliable and consistent set of five different foreign Pressure Broadening coefficients for the same HCl P(5) line has been measured by a consistent metrological approach covering Pressures from 100 to 600 hPa at temperatures of 294 and 295 K. The relative uncertainties of the stated CO2, N2, Ar, O2 and Air Pressure Broadening coefficients are in 1–3% range. The results are compared to previously available literature data—two Broadening coefficients have been improved in accuracy and two have been determined for the first time in the sub 1000 hPa Pressure range
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collision induced line parameters for the 2 0 overtone band of hcl 1 76 µm in binary mixtures with h2 and ch4
Journal of Quantitative Spectroscopy & Radiative Transfer, 2017Co-Authors: Alexandra V Domanskaya, Volker Ebert, H Tran, Michael GisiAbstract:Abstract We present experimental results on Pressure Broadening and shift coefficients in the first vibrational overtone band of HCl in gaseous mixtures with H 2 and CH 4 at room temperature. The whole set of collisional parameters for HCl–CH 4 is novel. Most of the data for HCl–H 2 system is also published for the first time. Our results have a precision of about 2% or better for shifts and below 1% for Broadening in the band center.
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laser based measurements of line strength self and Pressure Broadening coefficients of the h35cl r 3 absorption line in the first overtone region for Pressures up to 1 mpa
Applied Physics B, 2010Co-Authors: P Ortwein, Volker Ebert, W Woiwode, Steven Wagner, M GisiAbstract:A high-resolution spectrometer based on a vertical-cavity surface-emitting laser (VCSEL) was developed and used to determine the line strength S(T 0)=12.53(11)×10−21 cm−1/(molec cm−2) and the self-Broadening coefficient \(\gamma^{0}_{\mathrm{HCl}}=0.021787(61)\) cm−1/atm of the R(3) absorption line in the first rovibrational overtone (2←0) band of H35Cl. Furthermore, the first laser-based high-Pressure study on the Pressure Broadening of HCl by He, N2 and \(\mathrm{O}_{2}(\gamma^{0}_{\mathrm{N}_{2}}=0.07292(5)\) cm−1/atm, \(\gamma^{0}_{\mathrm{He}}=0.02113(1)\) cm−1/atm, \(\gamma^{0}_{\mathrm{O}_{2}}=0.03978(6)\) cm−1/atm) is presented covering Pressures of up to 1 MPa. The results are compared to previously available low-Pressure data.
Heinz-wilhelm Hübers - One of the best experts on this subject based on the ideXlab platform.
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high resolution gas phase spectroscopy with a distributed feedback terahertz quantum cascade laser
Applied Physics Letters, 2006Co-Authors: Heinz-wilhelm Hübers, Alexey Semenov, Lukas Mahler, Alessandro Tredicucci, Harvey E. Beere, Heiko Richter, S G Pavlov, David A. RitchieAbstract:The quantum cascade laser is a powerful, narrow linewidth, and continuous wave source of terahertz radiation. The authors have implemented a distributed feedback device in a spectrometer for high-resolution gas phase spectroscopy. Amplitude as well as frequency modulation schemes have been realized. The absolute frequency was determined by mixing the radiation from the quantum cascade laser with that from a gas laser. The Pressure Broadening and the Pressure shift of a rotational transition of methanol at 2.519THz were measured in order to demonstrate the performance of the spectrometer.The quantum cascade laser is a powerful, narrow linewidth, and continuous wave source of terahertz radiation. The authors have implemented a distributed feedback device in a spectrometer for high-resolution gas phase spectroscopy. Amplitude as well as frequency modulation schemes have been realized. The absolute frequency was determined by mixing the radiation from the quantum cascade laser with that from a gas laser. The Pressure Broadening and the Pressure shift of a rotational transition of methanol at 2.519THz were measured in order to demonstrate the performance of the spectrometer.
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high resolution gas phase spectroscopy with a distributed feedback terahertz quantum cascade laser
Applied Physics Letters, 2006Co-Authors: Heinz-wilhelm Hübers, Alexey Semenov, Lukas Mahler, Alessandro Tredicucci, Harvey E. Beere, Heiko Richter, S G Pavlov, David A. RitchieAbstract:The quantum cascade laser is a powerful, narrow linewidth, and continuous wave source of terahertz radiation. The authors have implemented a distributed feedback device in a spectrometer for high-resolution gas phase spectroscopy. Amplitude as well as frequency modulation schemes have been realized. The absolute frequency was determined by mixing the radiation from the quantum cascade laser with that from a gas laser. The Pressure Broadening and the Pressure shift of a rotational transition of methanol at 2.519THz were measured in order to demonstrate the performance of the spectrometer.
David A Hostutler - One of the best experts on this subject based on the ideXlab platform.
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Pressure Broadening and shift of the rubidium d1 transition and potassium d2 transitions by various gases with comparison to other alkali rates
Journal of Quantitative Spectroscopy & Radiative Transfer, 2014Co-Authors: Greg A Pitz, Andrew J Sandoval, Wade L Klennert, Tiffany B Tafoya, David A HostutlerAbstract:Abstract The Pressure Broadening and shift rates for the K D 2 ( 4 P 3 / 2 2 ← 4 S 1 / 2 2 ) transition with N 2 , CH 4 , C 2 H 6 , C 3 H 8 , n -C 4 H 10 , and the noble gases were obtained for Pressures up to 80 Torr and at a temperature of 55 °C by means of laser absorption spectroscopy. Additionally, the Broadening and shift rates for the Rb D 1 ( 5 P 1 / 2 2 ← 5 S 1 / 2 2 ) transition for He, CH 4 , C 2 H 6 , C 3 H 8 , and n -C 4 H 10 were obtained using the same techniques and under similar conditions. The K D 2 collisional Broadening rate, γ L , for He, Ne, Ar, Kr, Xe, N 2 , CH 4 , C 2 H 6 , C 3 H 8 , and n -C 4 H 10 are 19.84, 8.88, 18.65, 19.17, 22.19, 18.98, 27.78, 27.60, 27.70, and 33.48 MHz/Torr, respectively. The uncertainty in the Broadening rates is typically less than 2.1%. The corresponding Pressure induced shift rates, δ , are 0.52, −2.06, −5.52, −5.42, −7.01, −5.66, −8.38, −8.04, −9.22, and −9.37 MHz/Torr with an uncertainty of less than 1.8%. The Rb D 1 collisional Broadening rates for He, CH 4 , C 2 H 6 , C 3 H 8 , and n -C 4 H 10 are 20.80, 32.78, 30.49, 33.05, and 29.61 with uncertainties typically less than 2.2%. The collisional shift rates for the Rb D 1 transition are 5.80, −6.96, −7.88, −8.61, and −9.43 with uncertainties on the order of 1.1%. A comparison with the other alkali Broadening and shift cross-sections is presented.
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Pressure Broadening and shift of the potassium d1 transition by the noble gases and n2 h2 hd d2 ch4 c2h6 c3h8 and n c4h10 with comparison to other alkali rates
Journal of Quantitative Spectroscopy & Radiative Transfer, 2012Co-Authors: Greg A Pitz, Nathan D Zameroski, Andrew J Sandoval, Wade L Klennert, David A HostutlerAbstract:Abstract The Pressure Broadening and shift rates for the potassium D 1 ( 4 2 P 1 / 2 ← 4 2 S 1 / 2 ) transition with the noble gases and 3He, H2, HD, D2, N2, CH4, C2H6, C3H8, and n-C4H10 were obtained for Pressures up to 80 Torr and at a temperature of 55 °C by means of laser absorption spectroscopy. The collisional Broadening rate, γ L , for He, 3He, Ne, Ar, Kr, Xe, H2, HD, D2, N2, CH4, C2H6, C3H8, and n-C4H10 are 13.08, 17.46, 6.14, 19.45, 16.64, 20.02, 22.15, 19.36, 17.47, 17.78, 29.35, 26.63, 27.27, and 27.85 MHz/Torr, respectively. The uncertainty in the Broadening rates is typically less than 1.6%. The corresponding Pressure induced shift rates, δ , are 1.63, 6.82, −1.27, −6.44, −5.42, −6.54, −5.34, −5.10, −4.70, −6.80, −7.41, −8.32, −8.59, and −8.80 MHz/Torr with a uncertainty of less than 2.4%. A comparison with the other alkali D1 Broadening cross-sections is presented.
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Pressure Broadening and collisional shift of the rb d2 absorption line by ch4 c2h6 c3h8 n c4h10 and he
Journal of Quantitative Spectroscopy & Radiative Transfer, 2011Co-Authors: Nathan D Zameroski, Gordon D Hager, Wolfgang Rudolph, Christopher J Erickson, David A HostutlerAbstract:Abstract The Pressure Broadening and shift rates of the rubidium D2 absorption line 52S1/2→52P3/2 (780.24 nm) with CH4, C2H6, C3H8, n-C4H10, and He were measured for Pressures ≤80 Torr using high-resolution laser spectroscopy. The Broadening rates γB for CH4, C2H6, C3H8, n-C4H10, and He are 28.0, 28.1, 30.5, 31.3, and 20.3 (MHz/Torr), respectively. The corresponding shift rates γS are −8.4, −8.8, −9.7, −10.0, and 0.39 (MHz/Torr), respectively. The measured rates of Rb for the hydrocarbon buffer gas series of this study are also compared to the theoretically calculated rates of a purely attractive van der Waals difference potential. Good agreement is found to exist between measured and theoretical rates.
Glen P Perram - One of the best experts on this subject based on the ideXlab platform.
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Pressure Broadening and shift rates for ar s p transitions observed in an ar he discharge
Journal of Quantitative Spectroscopy & Radiative Transfer, 2016Co-Authors: Ben Eshel, Christopher A Rice, Glen P PerramAbstract:Abstract The Pressure Broadening and shift rates have been measured for the 801.699 nm ( s 5 → p 8 ) , 800.836 nm ( s 4 → p 6 ) and 795.036 nm ( s 3 → p 4 ) transitions in argon perturbed by 10–200 Torr of helium and argon at a temperature of 440 ± 20 K using a radio-frequency, capacitively coupled discharge. For a 10% Ar in He plasma the Pressure Broadening and shift rates were measured as 14.18 ± 0.65 and 1.81 ± 0.30 MHz / Torr , 17.85 ± 0.78 and 0.72 ± 0.32 MHz / Torr , and 16.59 ± 1.22 and 2.94 ± 0.48 MHz / Torr for the 801.699 nm, 800.836 nm and 795.036 nm transitions, respectively. The influence of the slightly varying gas temperature on the Broadening and shift rates is less than 1%. Stark Broadening and shifting by electrons in the discharge are not measurable due to low electron densities and temperatures. Phase-changing collisional cross-sections in the literature decrease with temperature, in good agreement with the Lindholm–Foley T − 0.2 trend based on the Lennard–Jones potential. Further investigation of the Ar ⁎ –Ar and Ar ⁎ –He interaction potentials is necessary to understand the behavior of the cross sections.
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Pressure Broadening and shift of the cesium d 2 transition by the noble gases and n 2 h 2 hd d 2 ch 4 c 2 h 6 cf 4 and he 3 with comparison to the d 1 transition
Physical Review A, 2010Co-Authors: Greg A Pitz, Charles D Fox, Glen P PerramAbstract:The Pressure Broadening and shift rates for the cesium ( ) transition with the noble gases and , , HD, , CH, H, CF, and were obtained for Pressures less than 300 Torr at a temperature of C by means of laser absorption spectroscopy. The collisional Broadening rate for He, Ne, Ar, Kr, Xe, , , HD, , CH, H, CF, and are 20.59, 9.81, 16.47, 15.54, 18.41, 19.18, 27.13, 28.24, 22.84, 25.84, 26.14, 17.81, and 22.35 MHz/Torr, respectively. The uncertainty in the Broadening rates is typically less than . The corresponding Pressure-induced shift rates are , , , , , , , , , , , , and MHz/Torr with an uncertainty of less than 0.04 MHz/Torr. With the exception of diatomic collision partners, the Broadening rates for Cs are -- less than the rates for Cs . For light collision partners with a blue shift, the is shifted more than the line. The Broadening cross sections for Cs and Rb are similar. However, the cross sections for K are about larger and for Na, about less.
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Pressure Broadening and shift of the cesium d 1 transition by the noble gases and n 2 h 2 hd d 2 ch 4 c 2 h 6 cf 4 and h 3 e
Physical Review A, 2009Co-Authors: Greg A Pitz, D Wertepny, Glen P PerramAbstract:The Pressure Broadening and shift rates for the cesium ${D}_{1}$ $(6\text{ }{^{2}P}_{1/2}\ensuremath{\leftarrow}6\text{ }{^{2}S}_{1/2})$ transition with the noble gases and ${\text{N}}_{2}$, ${\text{H}}_{2}$, HD, ${\text{D}}_{2}$, ${\text{CH}}_{4}$, ${\text{C}}_{2}{\text{H}}_{6}$, ${\text{CF}}_{4}$, and $^{3}\text{H}\text{e}$ were obtained for Pressures less than 300 torr at temperatures under $65\text{ }\ifmmode^\circ\else\textdegree\fi{}\text{C}$ by means of laser absorption spectroscopy. The collisional Broadening rate, ${\ensuremath{\gamma}}_{L}$, for He, Ne, Ar, Kr, Xe, ${\text{N}}_{2}$, ${\text{H}}_{2}$, HD, ${\text{D}}_{2}$, ${\text{CH}}_{4}$, ${\text{C}}_{2}{\text{H}}_{6}$, ${\text{CF}}_{4}$, and $^{3}\text{H}\text{e}$ are 24.13, 10.85, 18.31, 17.82, 19.74, 16.64, 20.81, 20.06, 18.04, 29.00, 26.70, 18.84, and 26.00 MHz/torr, respectively. The corresponding Pressure-induced shift rates, $\ensuremath{\delta}$, are 4.24, $\ensuremath{-}1.60$, $\ensuremath{-}6.47$, $\ensuremath{-}5.46$, $\ensuremath{-}6.43$, $\ensuremath{-}7.76$, 1.11, 0.47, 0.00, $\ensuremath{-}9.28$, $\ensuremath{-}8.54$, $\ensuremath{-}6.06$, and 6.01 MHz/torr. These rates have then been utilized to calculate Lennard-Jones potential coefficients to quantify the interatomic potential surfaces. The Broadening cross section has also been shown to correlate with the polarizability of the collision partner.
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Pressure Broadening of the d1 and d2 lines in diode pumped alkali lasers
Proceedings of SPIE the International Society for Optical Engineering, 2008Co-Authors: Greg A Pitz, Glen P PerramAbstract:The absolute absorption and stimulated emission cross-sections, including the effects of hyperfine splitting and Pressure Broadening at low to moderate Pressures are computed and compared with experimental results. The comparison is excellent and requires no fit parameters. An analysis of the degree to which the lineshape can be approximated by a single Lorentzian profile is provided as a function of background Pressure.