The Experts below are selected from a list of 216 Experts worldwide ranked by ideXlab platform
Michael Jackson - One of the best experts on this subject based on the ideXlab platform.
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Characterizing Far-Infrared Laser Emissions and the Measurement of Their Frequencies.
Journal of visualized experiments : JoVE, 2015Co-Authors: Michael Jackson, L. R. ZinkAbstract:The generation and subsequent measurement of Far-Infrared radiation has found numerous applications in high-resolution spectroscopy, radio astronomy, and Terahertz imaging. For about 45 years, the generation of coherent, Far-Infrared radiation has been accomplished using the optically pumped molecular Laser. Once Far-Infrared Laser radiation is detected, the frequencies of these Laser emissions are measured using a three-Laser heterodyne technique. With this technique, the unknown frequency from the optically pumped molecular Laser is mixed with the difference frequency between two stabilized, infrared reference frequencies. These reference frequencies are generated by independent carbon dioxide Lasers, each stabilized using the fluorescence signal from an external, low pressure reference cell. The resulting beat between the known and unknown Laser frequencies is monitored by a metal-insulator-metal point contact diode detector whose output is observed on a spectrum analyzer. The beat frequency between these Laser emissions is subsequently measured and combined with the known reference frequencies to extrapolate the unknown Far-Infrared Laser frequency. The resulting one-sigma fractional uncertainty for Laser frequencies measured with this technique is ± 5 parts in 10(7). Accurately determining the frequency of Far-Infrared Laser emissions is critical as they are often used as a reference for other measurements, as in the high-resolution spectroscopic investigations of free radicals using Laser magnetic resonance. As part of this investigation, difluoromethane, CH2F2, was used as the Far-Infrared Laser medium. In all, eight Far-Infrared Laser frequencies were measured for the first time with frequencies ranging from 0.359 to 1.273 THz. Three of these Laser emissions were discovered during this investigation and are reported with their optimal operating pressure, polarization with respect to the CO2 pump Laser, and strength.
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New Far-Infrared Laser Emissions from Optically Pumped $^{13}{\rm CHD}_{2}{\rm OH}$
IEEE Journal of Quantum Electronics, 2014Co-Authors: Sumaya Ifland, Mark Mcknight, Patrick Penoyar, Michael JacksonAbstract:The 13CHD2OH isotopic form of methanol has been investigated as a Far-Infrared Laser medium for wavelengths above 100 μm using a recently constructed optically pumped molecular Laser system. This system, which utilizes a transverse pumping geometry of the Far-Infrared Laser medium, has generated 43 new Far-Infrared Laser emissions ranging in wavelength from 106.4 to 700.3 μm. Along with the wavelength, each Laser emission is reported with its optimal operating pressure, polarization with respect to the CO2 pump Laser, and relative intensity.
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A spectroscopic study of the 14NH radical in vibrationally excited levels of the X 3Σ- state by Far-Infrared Laser magnetic resonance
Molecular Physics, 2007Co-Authors: Andrew Robinson, John M. Brown, Jesus Flores-mijangos, Lyndon Zink, Michael JacksonAbstract:Rotational transitions of vibrationally excited 14NH (υ = 1 and 2) in the ground X 3Σ- electronic state have been detected by Far-Infrared Laser magnetic resonance. The first four rotational intervals were investigated (N = 1 ← 0, 2 ← 1, 3 ← 2, and 4 ← 3) with a total of 17 Far-Infrared Laser lines ranging in wavelength from 81.1 to 373.6 μm. For some rotational intervals, transitions between all components of the Zeeman manifolds were observed. An effective Hamiltonian was used to model the experimental measurements. The magnetic hyperfine parameters have been determined for the first time for the υ = 2 level and have been significantly improved for the υ = 1 level. In addition, the rotational, centrifugal distortion, spin-spin, spin-rotation, and Zeeman parameters have all been experimentally determined for the υ = 1 and 2 levels of 14NH.
E. C. C. Vasconcellos - One of the best experts on this subject based on the ideXlab platform.
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Optically-Pumped Far-Infrared Laser Lines of Methanol Isotopomers: 12CH3OH, 12CH3OD, and 12CH2DOH
International Journal of Infrared and Millimeter Waves, 2000Co-Authors: E. C. C. Vasconcellos, L. R. Zink, S. C. Zerbetto, K. M. EvensonAbstract:Twenty-seven new Far-Infrared Laser lines from the isotopomers of methanol: ^12CD_3OH, ^12CH_3OD, and ^12CH_2DOH, were obtained by optically-pumping the molecules with an efficient cw CO_2 Laser. The CO_2 Laser provided pumping from regular, sequence, and hot-band CO_2 Laser transitions. The 2-m long Far-Infrared cavity was a metal-dielectric waveguide closed by two, flat end mirrors. Several short-wavelength (below 100 μm) lines were observed. The frequencies of 28 Laser lines observed in this cavity (including new lines and already known lines) were measured with a fractional uncertainty limited by the fractional resetability of the Far-Infrared Laser cavity, of 2 parts in 10^7.
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Optically-Pumped Far-Infrared Laser Lines in Hydrazine, Methanol, Heavy Water, and Ammonia: New Laser Lines and Frequency Measurements
International Journal of Infrared and Millimeter Waves, 2000Co-Authors: E. C. C. Vasconcellos, L. R. Zink, M. D. Allen, K. M. EvensonAbstract:A Far-Infrared Laser cavity designed to favor short-wavelength Laser lines was used to generate optically-pumped Far-Infrared Laser radiation. New Far-Infrared Laser lines were discovered in hydrazine, heavy water, ammonia, and several short-wavelength lines previously discovered in methanol were observed. Wavelength, frequency, and relative intensity measurements were performed on Laser lines in the wavelength range 42.4 to 253.7 μm. Each Far-Infrared frequency measurement was obtained by mixing the Far-Infrared radiation with radiation from two reference CO_2 Lasers and from a microwave synthesizer in a metal-insulator-metal diode. The pump Laser was a high-Q Fabry Perot resonator oscillating on 275 grating-selected Laser lines including regular, sequence, and hot band lines.
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Optically Pumped Far-Infrared Laser Lines of Methanol Isotopomers: 12CD3OH, 12CH3OD, and 12CH2DOH
International Journal of Infrared and Millimeter Waves, 2000Co-Authors: E. C. C. Vasconcellos, L. R. Zink, S. C. Zerbetto, K. M. EvensonAbstract:Twenty-seven new FIR, Far-Infrared, Laser lines from the isotopomers of methanol: ^12CD_3OH, ^12CH_3OD, and ^12CH_2DOH, were obtained by optically pumping the molecules with an efficient cw CO_2 Laser. The CO_2 Laser provided pumping from regular, sequence, and hot-band CO_2 Laser transitions. The 2 m long Far-Infrared cavity was a metal-dielectric waveguide closed by two, flat end mirrors. Several short-wavelength (below 100 μm) lines were observed. The frequencies of 28 Laser lines observed in this cavity (including new lines and already known lines) were measured with a fractional uncertainty limited by the fractional resetability of the Far-Infrared Laser cavity, of 2 parts in 10^7.
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New Far-Infrared Laser Lines and Frequency Measurements of Acetaldehyde and Vinyl Fluoride
International Journal of Infrared and Millimeter Waves, 1998Co-Authors: E. C. C. Vasconcellos, R. M. Lees, L. R. Zink, S. C. Zerbetto, K. M. EvensonAbstract:Eight Far-Infrared Laser lines have been obtained by optically pumping acetaldehyde (CH_3CHO) and nine by pumping vinyl fluoride (CH_2CHF) with a cw CO_2 Laser. The Far-Infrared Laser structure used a metal-dielectric waveguide cavity. This is the first reported observation of four of the Laser lines in acetaldehyde. In this work, we measure the frequency, optimum pressure of operation, relative intensity, relative polarization, and pump offset from CO_2 Laser-line center.
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New NH2H4 Far-Infrared Laser lines and their frequencies
International Journal of Infrared and Millimeter Waves, 1996Co-Authors: S. C. Zerbetto, Kenneth M. Evenson, Lyndon R. Zink, E. C. C. VasconcellosAbstract:We report 25 new Far-Infrared Laser lines and 26 heterodyne frequency measurements in hydrazine. The frequencies range from 1.0 to 5.5 THz with most of the frequencies between 2.5 and 4.0 THz. The lines were generated in a high frequency, Far-Infrared Fabry-Perot Laser cavity pumped by a CO2 Laser. The cavity has a high Q for wavelengths below 150 µm and uses variable coupling to optimize the power for each line.
M Jackson - One of the best experts on this subject based on the ideXlab platform.
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Using Guide Wavelengths to Assess Far-Infrared Laser Emissions
Journal of Infrared Millimeter and Terahertz Waves, 2015Co-Authors: B. Deshano, L. R. Zink, K. Olivier, B. Cain, M JacksonAbstract:An optically pumped molecular Laser system with a transverse excitation scheme has been used to observe 77 guide wavelengths associated with the modes of an oversized waveguide Laser resonator. These guide wavelengths, spanning from 102.6 to 990.6 μ m, were generated by a variety of lasing media, including methanol along with several symmetric- and asymmetric-top molecules. The guide wavelengths displayed several consistent characteristics when compared with their respective fundamental Laser emissions: their wavelengths were about 0.47 % larger and their relative powers were at least a factor of ten weaker. The properties of these guide wavelengths were used to assess frequency and wavelength measurements associated with known Far-Infrared Laser emissions. For several of these Laser emissions, this prompted a reinvestigation and subsequent revision of their measured values. Five Far-Infrared Laser frequencies were also measured for the first time.
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New cw Optically Pumped Far-Infrared Laser Emissions Generated with a Transverse or ‘Zig-Zag’ Pumping Geometry
Journal of Infrared Millimeter and Terahertz Waves, 2014Co-Authors: M Jackson, H. Alves, R. Holman, R. Minton, L. R. ZinkAbstract:This work reports the observation of several novel Far-Infrared Laser lines obtained through optical pumping of a gaseous medium using a transverse or zig-zag excitation scheme. In total, about 160 Laser emissions with wavelengths up to 1.1 mm have been observed. This includes nine new Laser lines detected from CH_3OD, CH_2 F_2, and CD_3 I which are reported with their operating pressure, relative power, and wavelengths measured to ± 0.5 μ m.
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Frequencies of cw FIR Laser lines for use in Laser magnetic resonance spectroscopy
Applied Physics B, 2008Co-Authors: L. R. Zink, A. Willcutt, M. Murphy, M JacksonAbstract:A transversely pumped Far-Infrared Laser cavity has been used to discover two optically pumped Laser lines: the 357.7 μm line from H_2C=CF_2 and the 242.3 μm line from CH_3OH. Using heterodyne techniques, the frequencies of fourteen Far-Infrared Laser emissions have been measured, six for the first time.
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Discovery and frequency measurement of short-wavelength Far-Infrared Laser emissions from optically pumped ^13CD_3OH and CHD_2OH
Applied Physics B, 2007Co-Authors: C. Uranga, L. R. Zink, C. Connell, G.m. Borstad, M JacksonAbstract:A three-Laser heterodyne system was used to measure the frequencies of twelve previously observed Far-Infrared Laser emissions from the partially deuterated methanol isotopologues ^13CD_3OH and CHD_2OH. Two Laser emissions, a 53.773 μm line from ^13CD_3OH and a 74.939 μm line from CHD_2OH, have also been discovered and frequency measured. The CO_2 pump Laser offset frequency was measured with respect to its center frequency for twenty-four FIR Laser emissions from CH_3OH, ^13CD_3OH and CHD_2OH.
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Measurement of Far-Infrared Laser frequencies generated by optically pumped N_ 2 H_4 and N_2D_4
Applied Physics B, 2005Co-Authors: M Jackson, B. Chuzles, C. Dirocco, P. Noffke, L. R. ZinkAbstract:A three-Laser heterodyne system has been used to measure the frequencies of four previously observed Far-Infrared Laser emissions generated by optically pumping either hydrazine (N_2H_4) or its fully deuterated isotope (N_2D_4) with a continuous-wave carbon dioxide Laser. These newly measured frequencies have fractional uncertainties of ± 2 × 10^−7 and correspond to Laser wavelengths ranging from 63.9 to 158.4 μm. This work represents the first measurement of a N_2D_4 Laser frequency.
L. R. Zink - One of the best experts on this subject based on the ideXlab platform.
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Characterizing Far-Infrared Laser Emissions and the Measurement of Their Frequencies.
Journal of visualized experiments : JoVE, 2015Co-Authors: Michael Jackson, L. R. ZinkAbstract:The generation and subsequent measurement of Far-Infrared radiation has found numerous applications in high-resolution spectroscopy, radio astronomy, and Terahertz imaging. For about 45 years, the generation of coherent, Far-Infrared radiation has been accomplished using the optically pumped molecular Laser. Once Far-Infrared Laser radiation is detected, the frequencies of these Laser emissions are measured using a three-Laser heterodyne technique. With this technique, the unknown frequency from the optically pumped molecular Laser is mixed with the difference frequency between two stabilized, infrared reference frequencies. These reference frequencies are generated by independent carbon dioxide Lasers, each stabilized using the fluorescence signal from an external, low pressure reference cell. The resulting beat between the known and unknown Laser frequencies is monitored by a metal-insulator-metal point contact diode detector whose output is observed on a spectrum analyzer. The beat frequency between these Laser emissions is subsequently measured and combined with the known reference frequencies to extrapolate the unknown Far-Infrared Laser frequency. The resulting one-sigma fractional uncertainty for Laser frequencies measured with this technique is ± 5 parts in 10(7). Accurately determining the frequency of Far-Infrared Laser emissions is critical as they are often used as a reference for other measurements, as in the high-resolution spectroscopic investigations of free radicals using Laser magnetic resonance. As part of this investigation, difluoromethane, CH2F2, was used as the Far-Infrared Laser medium. In all, eight Far-Infrared Laser frequencies were measured for the first time with frequencies ranging from 0.359 to 1.273 THz. Three of these Laser emissions were discovered during this investigation and are reported with their optimal operating pressure, polarization with respect to the CO2 pump Laser, and strength.
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Using Guide Wavelengths to Assess Far-Infrared Laser Emissions
Journal of Infrared Millimeter and Terahertz Waves, 2015Co-Authors: B. Deshano, L. R. Zink, K. Olivier, B. Cain, M JacksonAbstract:An optically pumped molecular Laser system with a transverse excitation scheme has been used to observe 77 guide wavelengths associated with the modes of an oversized waveguide Laser resonator. These guide wavelengths, spanning from 102.6 to 990.6 μ m, were generated by a variety of lasing media, including methanol along with several symmetric- and asymmetric-top molecules. The guide wavelengths displayed several consistent characteristics when compared with their respective fundamental Laser emissions: their wavelengths were about 0.47 % larger and their relative powers were at least a factor of ten weaker. The properties of these guide wavelengths were used to assess frequency and wavelength measurements associated with known Far-Infrared Laser emissions. For several of these Laser emissions, this prompted a reinvestigation and subsequent revision of their measured values. Five Far-Infrared Laser frequencies were also measured for the first time.
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New cw Optically Pumped Far-Infrared Laser Emissions Generated with a Transverse or ‘Zig-Zag’ Pumping Geometry
Journal of Infrared Millimeter and Terahertz Waves, 2014Co-Authors: M Jackson, H. Alves, R. Holman, R. Minton, L. R. ZinkAbstract:This work reports the observation of several novel Far-Infrared Laser lines obtained through optical pumping of a gaseous medium using a transverse or zig-zag excitation scheme. In total, about 160 Laser emissions with wavelengths up to 1.1 mm have been observed. This includes nine new Laser lines detected from CH_3OD, CH_2 F_2, and CD_3 I which are reported with their operating pressure, relative power, and wavelengths measured to ± 0.5 μ m.
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Frequencies of cw FIR Laser lines for use in Laser magnetic resonance spectroscopy
Applied Physics B, 2008Co-Authors: L. R. Zink, A. Willcutt, M. Murphy, M JacksonAbstract:A transversely pumped Far-Infrared Laser cavity has been used to discover two optically pumped Laser lines: the 357.7 μm line from H_2C=CF_2 and the 242.3 μm line from CH_3OH. Using heterodyne techniques, the frequencies of fourteen Far-Infrared Laser emissions have been measured, six for the first time.
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Discovery and frequency measurement of short-wavelength Far-Infrared Laser emissions from optically pumped ^13CD_3OH and CHD_2OH
Applied Physics B, 2007Co-Authors: C. Uranga, L. R. Zink, C. Connell, G.m. Borstad, M JacksonAbstract:A three-Laser heterodyne system was used to measure the frequencies of twelve previously observed Far-Infrared Laser emissions from the partially deuterated methanol isotopologues ^13CD_3OH and CHD_2OH. Two Laser emissions, a 53.773 μm line from ^13CD_3OH and a 74.939 μm line from CHD_2OH, have also been discovered and frequency measured. The CO_2 pump Laser offset frequency was measured with respect to its center frequency for twenty-four FIR Laser emissions from CH_3OH, ^13CD_3OH and CHD_2OH.
A. Harth - One of the best experts on this subject based on the ideXlab platform.
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Power broadening and the basic limitations of CW optically pumped Far-Infrared Laser performance
IEEE Journal of Quantum Electronics, 1995Co-Authors: A. HarthAbstract:Power broadening is shown to be important for the line profile of the pump absorption coefficient of optically pumped Far-Infrared Laser gases. Calculations of the pump absorption have to account for power broadening in order to correctly represent the flow of energy during the Laser cycle. An analytic expression is derived for the power broadened absorption in the case of resonantly pumping the center of the absorption line. The basic limitations of Far-Infrared Laser performance are the maximum pump power per volume that a molecular gas can absorb as well as the maximum Far-Infrared power per volume that the gas is able to produce. Closed expressions evolving from the power broadening considerations are given for both quantities. It turns out that both are basically determined by only two physical properties of the Laser gas, namely the energy of the lower pump level and the rotational relaxation rate. >
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Optically pumped Far-Infrared Laser with sandwich resonator
Optical and Quantum Electronics, 1992Co-Authors: A. HarthAbstract:A new resonator geometry for optically pumped Far-Infrared Lasers is suggested. First experimental results of a transversely pumped CW Laser are reported.
