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John M Doyle - One of the best experts on this subject based on the ideXlab platform.
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probing Buffer Gas cooled molecules with direct frequency comb spectroscopy in the mid infrared
Frontiers in Optics, 2015Co-Authors: Ben Spaun, David Patterson, P B Changala, Bryce J Bjork, Oliver H Heckl, Jun Ye, John M DoyleAbstract:We demonstrate cavity-enhanced direct frequency comb spectroscopy on Buffer-Gas cooled molecules. By coupling a mid-infrared frequency comb to a high-finesse cavity surrounding a 4 K Buffer-Gas chamber, we obtain rotationally resolved absorption spectra of multiple vibrational bands of nitromethane.
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Buffer Gas loaded magneto optical traps for yb tm er and ho
New Journal of Physics, 2014Co-Authors: John M Doyle, Boerge Hemmerling, Garrett Drayna, Eunmi Chae, Aakash RaviAbstract:Direct loading of lanthanide atoms into magneto-optical traps (MOTs) from a very slow cryogenic Buffer Gas beam source is achieved, without the need for laser slowing. The beam source has an average forward velocity of 60– and a velocity half-width of , which allows for direct MOT loading of Yb, Tm, Er and Ho. Residual helium background Gas originating from the beam results in a maximum trap lifetime of about 80 ms (with Yb). The addition of a single-frequency slowing laser applied to the Yb in the Buffer Gas beam increases the number of trapped Yb atoms to with a loading rate of . Decay to metastable states is observed for all trapped species and decay rates are measured. Extension of this approach to the loading of molecules into a MOT is discussed.
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the Buffer Gas beam an intense cold and slow source for atoms and molecules
Chemical Reviews, 2012Co-Authors: Nicholas R. Hutzler, Hsini Lu, John M DoyleAbstract:Beams of atoms and molecules are stalwart tools for spectroscopy and studies of collisional processes. The supersonic expansion technique can create cold beams of many species of atoms and molecules. However, the resulting beam is typically moving at a speed of 300−600 m s^(−1) in the laboratory frame and, for a large class of species, has insufficient flux (i.e., brightness) for important applications. In contrast, Buffer Gas beams can be a superior method in many cases, producing cold and relatively slow atoms and molecules (see Figure 1) in the laboratory frame with high brightness and great versatility. There are basic differences between supersonic and Buffer Gas cooled beams regarding particular technological advantages and constraints. At present, it is clear that not all of the possible variations on the Buffer Gas method have been studied. In this review, we will present a survey of the current state of the art in Buffer Gas beams, and explore some of the possible future directions that these new methods might take.
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intense atomic and molecular beams via neon Buffer Gas cooling
New Journal of Physics, 2009Co-Authors: David Patterson, Julia Rasmussen, John M DoyleAbstract:We realize a continuous, intense, cold molecular and atomic beam source based on Buffer-Gas cooling. Hot vapor (up to 600 K) from an oven is mixed with cold (15 K) neon Buffer Gas, and then emitted into a high-flux beam. The novel use of cold neon as a Buffer Gas produces a forward velocity distribution and low-energy tail that is comparable to much colder helium-based sources. We expect this source to be trivially generalizable to a very wide range of atomic and molecular species with significant vapor pressure below 1000 K. The source has properties that make it a good starting point for laser cooling of molecules or atoms, cold collision studies, trapping, or nonlinear optics in Buffer-Gas-cooled atomic or molecular Gases. A continuous guided beam of cold deuterated ammonia with a flux of 3×1011 ND3 molecules s−1 and a continuous free-space beam of cold potassium with a flux of 1×1016 K atoms s−1 are realized.
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realization of coherent optically dense media via Buffer Gas cooling
Physical Review A, 2009Co-Authors: John M Doyle, David Patterson, Tao Hong, Alexey V Gorshkov, A S Zibrov, Mikhail D Lukin, Mara PrentissAbstract:We demonstrate that Buffer-Gas cooling combined with laser ablation can be used to create coherent optical media with high optical depth and low Doppler broadening that offers metastable states with low collisional and motional decoherence. Demonstration of this generic technique opens pathways to coherent optics with a large variety of atoms and molecules. We use helium Buffer Gas to cool $^{87}\mathrm{Rb}$ atoms to below $7\phantom{\rule{0.3em}{0ex}}\mathrm{K}$ and slow atom diffusion to the walls. Electromagnetically induced transparency in this medium allows for 50% transmission in a medium with initial optical depth $Dg70$ and for slow pulse propagation with large delay-bandwidth products. In the high-$D$ regime, we observe high-contrast spectrum oscillations due to efficient four-wave mixing.
Raymond J. Beach - One of the best experts on this subject based on the ideXlab platform.
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Resonance transition 795-nm rubidium laser using He Buffer Gas
High-Power Laser Ablation VII, 2008Co-Authors: Sheldon Wu, Thomas F. Soules, Ralph H. Page, Scott C. Mitchell, V. Keith Kanz, Raymond J. BeachAbstract:Resonance transition rubidium laser (5 2 P 1/2 →5 2 S 1/2 ) is demonstrated with a hydrocarbon-free Buffer Gas. Prior demonstrations of alkali resonance transition lasers have used ethane as either the Buffer Gas or a Buffer Gas component to promote rapid fine-structure mixing. However, our experience suggests that the alkali vapor reacts with the ethane producing carbon as one of the reaction products. This degrades long term laser reliability. Our recent experimental results with a "clean" helium-only Buffer Gas system pumped by a Ti:sapphire laser demonstrate all the advantages of the original alkali laser system, but without the reliability issues associated with the use of ethane. We further report a demonstration of a rubidium laser using a Buffer Gas consisting of pure 3 He. Using isotopically enriched 3 He Gas yields enhanced mixing of the Rb fine-structure levels. This enables efficient lasing at reduced He Buffer Gas pressure, improved thermal management in high average power Rb lasers and enhanced power scaling potential of such systems.
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resonance transition 795 nm rubidium laser using 3he Buffer Gas
Optics Communications, 2008Co-Authors: Thomas F. Soules, Ralph H. Page, Scott C. Mitchell, Sheldon S Q Wu, Keith V Kanz, Raymond J. BeachAbstract:Abstract We report a demonstration of a 795-nm rubidium optical resonance transition laser using a Buffer Gas consisting of pure 3 He. This follows our recent demonstration of a hydrocarbon-free 795-nm rubidium resonance laser which used naturally-occurring He as the Buffer Gas. Using He Gas that is isotopically enriched with 3 He yields enhanced mixing of the Rb fine-structure levels. This enables efficient lasing at reduced He Buffer Gas pressure, improved thermal management in high average power Rb lasers and enhanced power scaling potential of such systems.
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resonance transition 795 nm rubidium laser using 3he Buffer Gas
Advanced Solid-State Photonics (2008) paper WB2, 2008Co-Authors: Sheldon S Q Wu, Thomas F. Soules, Ralph H. Page, Scott C. Mitchell, Keith V Kanz, Raymond J. BeachAbstract:Demonstration of 795-nm Rubidium laser using a Buffer Gas consisting of pure3He is reported. The use of3He yields enhanced mixing of Rb fine-structure levels and enables efficient lasing at reduced Buffer Gas pressures.
George R Welch - One of the best experts on this subject based on the ideXlab platform.
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Influence of a Buffer Gas on nonlinear magneto-optical polarization rotation
Journal of The Optical Society of America B-optical Physics, 2005Co-Authors: Irina Novikova, Andrey B. Matsko, George R WelchAbstract:We show experimentally that the presence of a Buffer Gas in a rubidium vapor cell modifies significantly the nonlinear magneto-optical rotation of polarization of near-resonant light propagating through the cell. We observe not only the well-known narrowing of the nonlinear magneto-optical resonances, but also changes in their shape and visibility. We explain these effects in terms of coherence-preserving, velocity-changing collisions between rubidium and Buffer Gas atoms.
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Buffer Gas induced absorption resonances in rb vapor
Physical Review A, 2004Co-Authors: E E Mikhailov, Irina Novikova, Yuri V Rostovtsev, George R WelchAbstract:We observe transformation of the electromagnetically induced transparency (EIT) resonance into an absorption resonance in a {lambda} interaction configuration in a cell filled with {sup 87}Rb and a Buffer Gas. This transformation occurs as one-photon detuning of the coupling fields is varied from the atomic transition. No such absorption resonance is found in the absence of a Buffer Gas. The width of the absorption resonance is several times smaller than the width of the EIT resonance, and the changes of absorption near these resonances are about the same. Similar absorption resonances are detected in the Hanle configuration in a Buffered cell.
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absorption resonance and large negative delay in rubidium vapor with a Buffer Gas
Journal of The Optical Society of America B-optical Physics, 2004Co-Authors: E E Mikhailov, Yuri V Rostovtsev, Vladimir A Sautenkov, George R WelchAbstract:We observe a narrow, isolated, two-photon absorption resonance in 87Rb for large one-photon detuning in the presence of a Buffer Gas. In the absence of a Buffer Gas, a standard Λ configuration of two laser frequencies gives rise to electromagnetically induced transparency (EIT) for all values of one-photon detuning throughout the inhomogeneously (Doppler) broadened line. However, when a Buffer Gas is added and the one-photon detuning is comparable to or greater than the Doppler width, an absorption resonance appears instead of the usual EIT resonance. We also observe a large negative group delay (≈−300 μs for a Gaussian pulse that propagates through the media with respect to a reference pulse not affected by the media), corresponding to a superluminal group velocity vg=−c/(3.6×106)=−84 m/s.
Luo Xizhang - One of the best experts on this subject based on the ideXlab platform.
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Selecting aspects of Buffer Gas in optically pumped far-infrared laser
Laser Technology, 2020Co-Authors: Luo XizhangAbstract:Based on semi-classical density matrix theory and SSH method, Buffer Gas effect of optically pumped far-infrared laser was theoretically studied and the effect of depth of potential well and radius of collision on Buffer Gas was analyzed.The result would do favor to find high-efficient Buffer Gas of optically pumped far-infrared laser and also had some instruction to its application.
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Temperature and Mass Aspect of Buffer Gas Effect on Optically Pumped Submillimeter Wave Laser
Laser & Infrared, 2020Co-Authors: Luo XizhangAbstract:Based on semi-classical density matrix theory and SSH method, Buffer Gas effect optically pumped submillimeter wave laser was theoretically studied and the effect of temperature and mass on Buffer Gas effect was analyzed. The result would do favor to find high-efficient Buffer Gas of optically pumped submillimeter wave laser,and also have some instructions to its application.
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Temperature and Mass Factor of Buffer Gas Effect in Optically Pumped Submillimeter Wave Laser
International Journal of Infrared and Millimeter Waves, 2004Co-Authors: Zhang Ping, Luo XizhangAbstract:Based on semi-classical density matrix theory and SSH theory, the effect of Buffer Gas in optically pumped submillimeter wave laser was theoretically studied and the effect of temperature and mass on the effect of Buffer Gas was analyzed, then the selection rules of Buffer Gas were achieved. The results could do favor to find high-efficient Buffer Gas of miniature optically pumped submillimeter wave laser and also had some instruction to its application.
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A Quantum-Mechanical Explanation of Buffer Gas Effect on Submillimeter Wave Laser
International Journal of Infrared and Millimeter Waves, 2003Co-Authors: Zhang Ping, Chen Weibin, Xiao Dongmei, Luo XizhangAbstract:Based on the theory of molecular vibration relaxation, the model of Buffer Gas effect was built up. By theoretically deducing the vibrational lower-level deactivation rate of operating Gas molecule with quantum mechanics, the selection rules of high-efficient Buffer Gas under different working conditions were educed and tested by experiments. The results could be helpful to the study of large-power wide-range efficient tunable miniature pulsed optically pumped submillimeter wave laser and its application.
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Effects of Buffer Gas on the output of optically pumped NH/sub 3/ far-infrared cavity laser
ICMMT 2000. 2000 2nd International Conference on Microwave and Millimeter Wave Technology Proceedings (Cat. No.00EX364), 2000Co-Authors: Huang Xiao, Luo Xizhang, Li Hongjian, Wang YangAbstract:By solving the semi-classical density matrix equations and developing a Buffer Gas mechanism model, the effects of Buffer Gas on the output power of optically pumped NH/sub 3/ far-infrared cavity laser were calculated and verified by experiment. Our results showed that: the output power of NH/sub 3/ far-infrared laser could be increased when a certain Buffer Gas was added into the laser medium, and there existed an optimum ratio of Gas mixture and an optimum operating Gas pressure which could make the output power of far-infrared laser reach a maximum.
Sheldon S Q Wu - One of the best experts on this subject based on the ideXlab platform.
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resonance transition 795 nm rubidium laser using 3he Buffer Gas
Optics Communications, 2008Co-Authors: Thomas F. Soules, Ralph H. Page, Scott C. Mitchell, Sheldon S Q Wu, Keith V Kanz, Raymond J. BeachAbstract:Abstract We report a demonstration of a 795-nm rubidium optical resonance transition laser using a Buffer Gas consisting of pure 3 He. This follows our recent demonstration of a hydrocarbon-free 795-nm rubidium resonance laser which used naturally-occurring He as the Buffer Gas. Using He Gas that is isotopically enriched with 3 He yields enhanced mixing of the Rb fine-structure levels. This enables efficient lasing at reduced He Buffer Gas pressure, improved thermal management in high average power Rb lasers and enhanced power scaling potential of such systems.
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resonance transition 795 nm rubidium laser using 3he Buffer Gas
Advanced Solid-State Photonics (2008) paper WB2, 2008Co-Authors: Sheldon S Q Wu, Thomas F. Soules, Ralph H. Page, Scott C. Mitchell, Keith V Kanz, Raymond J. BeachAbstract:Demonstration of 795-nm Rubidium laser using a Buffer Gas consisting of pure3He is reported. The use of3He yields enhanced mixing of Rb fine-structure levels and enables efficient lasing at reduced Buffer Gas pressures.
