Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

光谱学与光谱分析

[Molecular coherent radiation in VUV/XUV regions and the determination of rotational temperature of molecule].

Xiaobo Xie, Ting Sun

Published Dec 1, 2001• 0 citations
OpenAlex

Abstract

The investigation of spectroscopy of vacuum ultraviolet (VUV, 100-200 nm) and extreme ultraviolet (XUV, 10-100 nm) regions has attracted the attention of many researchers in recent years because of its promising applications in such areas as spectroscopy of highly excited states of atoms and molecules, life science, plasma physics and material science. In this paper we report the study of molecular coherent spectrum in the VUV and XUV regions through nonlinear optical processes and the determination of the rotational temperature of molecules. Because molecular gases have abundant energy levels, it can provide resonant levels to enhance the generated radiation and a wide tunibility of the spectrum in VUV and XUV regions. The determination of the rotational temperature of molecules will be very useful for the study of molecular spectroscopy and the nonlinear optical process in VUV/XUV regions.

Related papers

A spectrally bright wavelength-switchable vacuum ultraviolet source driven by quantum coherence in strong-field-ionized molecules

Yuexin Wan, Zhaoxiang Liu, Jinping Yao +6 more

Abstract We report generation of spectrally bright vacuum ultraviolet (VUV) and deep UV (DUV) coherent radiations at the wavelengths of 192 nm, 198 nm and 204 nm. These DUV/VUV radiations originate from resonant four-wave mixing assisted by quantum coherence in tunnel-ionized CO molecules. The electronic coherence is created when the pump pulses resonantly excite electronic transitions of CO+. The technique allows for the selective switch of DUV/VUV wavelengths provided by the abundant energy levels of molecular ions. The developed source can have arbitrary polarization states by manipulating the polarization of the pump pulse. It also exhibits a spectral bandwidth of 5∼7 cm−1, a divergence angle of 3∼5 mrad, a pulse duration of ∼10 ps, and a photon flux of ∼1010 photons/s. The superior temporal and spectral properties give rise to a broadband Raman comb in the DUV/VUV region.

arXiv:2007.11900•New Journal of Physics•Jan 21, 2021•6 citations

Generation of continuously tunable coherent vacuum-ultraviolet radiation in Cd vapor

Kenzo Miyazaki, Hirofumi Sakai, Takuzo Sato

Continuously tunable coherent vacuum-ultraviolet (VUV) radiation has been generated in the 128.7-135.3-nm region by two-photon resonant four-wave mixing in Cd vapor. The generated VUV has no spectral structure over the tuning range and indicates that Cd vapor is an efficient nonlinear medium for frequency conversion.

Optics Letters•Oct 1, 1984•14 citations

Ultrafast control and opto-optical modulation of extreme ultraviolet light

Samuel Bengtsson, J. Mauritsson

Abstract Ultrashort, coherent light pulses in the extreme ultraviolet (XUV) wavelength region are excellent tools for a wide range of experiments. These XUV pulses are in particular used to characterize electron dynamics. Additionally, the high photon energy enables quantum control of short-lived transitions in atoms. These transitions are of interest for ultrafast quantum control as the bandwidth of the control pulses needs to be less than the transition frequency. Coherent XUV pulses would be even more useful if the tools to control and manipulate them existed. Presently, however, no modulators exist for these frequencies, which significantly reduces the number of possible ultrafast optics experiments and applications in the XUV regime. This Ph.D. tutorial addresses this problem and focuses on the control of XUV light in time and space. To enable control of XUV light we have developed a method for opto-optical modulation (OOM), which modulates the phase of XUV light emitted from a gas of atoms. The atoms are resonantly excited with a coherent XUV pulse generated through high order harmonic generation and emit light after the excitation pulse passed. By shifting the resonance frequencies through the AC Stark shift with a non-resonant infrared control pulse, the phase of the emitted light, and therefore its wavefront, is controlled. With OOM the direction of XUV light emitted from noble gases has been controlled, and the temporal dynamics of the emission studied. By varying the delay between the excitation and the control pulse, the time of redirection was controlled, which enabled high signal to noise study of the temporal dynamics of the emission. Furthermore, a proof-of-principle experiment with two control pulses was performed, resulting in a shaped XUV pulse with controlled duration. The technique of OOM presented in this article is still at a very early stage and in order to obtain complete control of the amplitude and phase of the XUV pulses further development is necessary. Such development would present new opportunities for ultrafast XUV quantum control.

Journal of Physics B Atomic Molecular and Optical Physics•Jan 24, 2019•14 citations

Nonlinear generation of extreme-ultraviolet radiation in atomic hydrogen using electromagnetically induced transparency

G. Z. Zhang, Dennis W. Tokaryk, Boris Peter Stoicheff +1 more

Sum-frequency generation enhanced by electromagnetically induced transparency (EIT) has been extended to the production of extreme ultraviolet (XUV) radiation in the range 97.3--92.6 nm from $np\ensuremath{-}1s$ transitions $(n=4--8)$ in atomic hydrogen. Pulsed radiation was generated by strong coupling of the $\mathrm{np}$ and $2s$ levels with laser radiation at Balmer wavelengths, and simultaneously (weaker) coupling of the $2s$ and $1s$ levels by two-photon resonance with 243-nm laser radiation. Investigations were carried out over a range of laser intensities and products of interaction length and atomic density $(\mathrm{NL}).$ As the product $\mathrm{NL}$ increased, the XUV intensities were greatly enhanced by EIT, and at high $\mathrm{NL}$ values, the spectral distributions of some of the generated signals were found to be distorted by the presence of molecular hydrogen. Calculated profiles, modified to incorporate the effects of nearby molecular resonances, were shown to be in good agreement with the observed spectra.

Physical Review A•Jul 1, 1997•20 citations

New methods for determining the polarization state of vacuum ultraviolet radiation

V. Yu. Bakman, Sergei V. Bobashev, Oleg S. Vasyutinskii

Two new methods are proposed for determining the polarization of vacuum ultraviolet radiation which permit the determination of an arbitrary polarization mode for photons with energies of 10–100 eV. The essence of these methods is to create and detect a nonequilibrium population of the magnetic sublevels of atoms and molecules excited by the original VUV radiation and then determine the polarization of this radiation based on these measurements in accordance with known formulas.

Technical Physics•Sep 1, 1999•2 citations

Coherent control of atoms and molecules.

Randy A. Bartels

Whenever scientific tools are significantly advanced; new discoveries soon follow. My thesis work relies on advances in ultrafast laser technology that allow precise control over the shape of sub 20-fs laser pulses. This laser system enabled many new experiments that yielded significant advances in attosecond science, atomic physics; extreme nonlinear optics, quantum chemistry, coherent control, molecular physics, ultrafast optical phase modulation, EUV coherent imagines, and EUV radiation sources. By using an automated learning control algorithm coupled to our deformable mirror pulse shaper; we have demonstrated the control of a process on an attosecond time-scale for the first time. We demonstrate the manipulation of the phase of an electron wave packet, allowing us to tailor the EUV spectrum generated by high-order harmonic generation. These optimal fields were discovered by a learning algorithm that both found an unknown optimal solution; but also discovered an unknown phase-matching mechanism that occurs in the interaction of a single atom and light pulse. We control molecular vibrational and rotational coherences with the same learning algorithm; demonstrating selective control in room temperature molecules at atmospheric pressures. Moreover, we demonstrate that modifications to the algorithm can help automatically uncover the physics of the control mechanism found by the learning algorithm. We also demonstrate a new pulse-compression technique using rotational phase modulation, where optical pulses were compressed by an order of magnitude after phase modulation by a molecular rotational coherence and subsequent propagation through a transparent window. This technique will enable efficient pulse compression in the deep-UV. Finally, we measure the coherence of EUV light generated by high-harmonic upconversion of a femtosecond laser. In phase-matched hollow-fiber geometry, the EUV light exhibits the highest inherent spatial coherence of any source in this region of the spectrum. We use this source to demonstrate the coherent image with first table-top EUV radiation. Since this source exhibits full spatial coherence at very short wavelength, this light source represents has smallest inherent effective source-size of any light source yet created. We also demonstrate that the spectrum of an optical field can be determined by measuring the interference of a double-slit pattern.

•Jan 1, 2002•5 citations
The investigation of spectroscopy of vacuum ultraviolet (VUV, 100-200 nm) and extreme ultraviolet (XUV, 10-100 nm) regions has attracted the attention of many researchers in recent years because of its promising applications in such areas as spectroscopy of highly excited states of atoms and molecules, life science, plasma physics and material science. In this paper we report the study of molecular coherent spectrum in the VUV and XUV regions through nonlinear optical processes and the determination of the rotational temperature of molecules. Because molecular gases have abundant energy levels, it can provide resonant levels to enhance the generated radiation and a wide tunibility of the spectrum in VUV and XUV regions. The determination of the rotational temperature of molecules will be very useful for the study of molecular spectroscopy and the nonlinear optical process in VUV/XUV regions.
Abstract We report generation of spectrally bright vacuum ultraviolet (VUV) and deep UV (DUV) coherent radiations at the wavelengths of 192 nm, 198 nm and 204 nm. These DUV/VUV radiations originate from resonant four-wave mixing assisted by quantum coherence in tunnel-ionized CO molecules. The electronic coherence is created when the pump pulses resonantly excite electronic transitions of CO+. The technique allows for the selective switch of DUV/VUV wavelengths provided by the abundant energy levels of molecular ions. The developed source can have arbitrary polarization states by manipulating the polarization of the pump pulse. It also exhibits a spectral bandwidth of 5∼7 cm−1, a divergence angle of 3∼5 mrad, a pulse duration of ∼10 ps, and a photon flux of ∼1010 photons/s. The superior temporal and spectral properties give rise to a broadband Raman comb in the DUV/VUV region.
Abstract Ultrashort, coherent light pulses in the extreme ultraviolet (XUV) wavelength region are excellent tools for a wide range of experiments. These XUV pulses are in particular used to characterize electron dynamics. Additionally, the high photon energy enables quantum control of short-lived transitions in atoms. These transitions are of interest for ultrafast quantum control as the bandwidth of the control pulses needs to be less than the transition frequency. Coherent XUV pulses would be even more useful if the tools to control and manipulate them existed. Presently, however, no modulators exist for these frequencies, which significantly reduces the number of possible ultrafast optics experiments and applications in the XUV regime. This Ph.D. tutorial addresses this problem and focuses on the control of XUV light in time and space. To enable control of XUV light we have developed a method for opto-optical modulation (OOM), which modulates the phase of XUV light emitted from a gas of atoms. The atoms are resonantly excited with a coherent XUV pulse generated through high order harmonic generation and emit light after the excitation pulse passed. By shifting the resonance frequencies through the AC Stark shift with a non-resonant infrared control pulse, the phase of the emitted light, and therefore its wavefront, is controlled. With OOM the direction of XUV light emitted from noble gases has been controlled, and the temporal dynamics of the emission studied. By varying the delay between the excitation and the control pulse, the time of redirection was controlled, which enabled high signal to noise study of the temporal dynamics of the emission. Furthermore, a proof-of-principle experiment with two control pulses was performed, resulting in a shaped XUV pulse with controlled duration. The technique of OOM presented in this article is still at a very early stage and in order to obtain complete control of the amplitude and phase of the XUV pulses further development is necessary. Such development would present new opportunities for ultrafast XUV quantum control.
Sum-frequency generation enhanced by electromagnetically induced transparency (EIT) has been extended to the production of extreme ultraviolet (XUV) radiation in the range 97.3--92.6 nm from $np\ensuremath{-}1s$ transitions (n=4−−8)(n=4--8)(n=4−−8) in atomic hydrogen. Pulsed radiation was generated by strong coupling of the np\mathrm{np}np and 2s2s2s levels with laser radiation at Balmer wavelengths, and simultaneously (weaker) coupling of the 2s2s2s and 1s1s1s levels by two-photon resonance with 243-nm laser radiation. Investigations were carried out over a range of laser intensities and products of interaction length and atomic density (NL).(\mathrm{NL}).(NL). As the product NL\mathrm{NL}NL increased, the XUV intensities were greatly enhanced by EIT, and at high NL\mathrm{NL}NL values, the spectral distributions of some of the generated signals were found to be distorted by the presence of molecular hydrogen. Calculated profiles, modified to incorporate the effects of nearby molecular resonances, were shown to be in good agreement with the observed spectra.
Whenever scientific tools are significantly advanced; new discoveries soon follow. My thesis work relies on advances in ultrafast laser technology that allow precise control over the shape of sub 20-fs laser pulses. This laser system enabled many new experiments that yielded significant advances in attosecond science, atomic physics; extreme nonlinear optics, quantum chemistry, coherent control, molecular physics, ultrafast optical phase modulation, EUV coherent imagines, and EUV radiation sources. By using an automated learning control algorithm coupled to our deformable mirror pulse shaper; we have demonstrated the control of a process on an attosecond time-scale for the first time. We demonstrate the manipulation of the phase of an electron wave packet, allowing us to tailor the EUV spectrum generated by high-order harmonic generation. These optimal fields were discovered by a learning algorithm that both found an unknown optimal solution; but also discovered an unknown phase-matching mechanism that occurs in the interaction of a single atom and light pulse. We control molecular vibrational and rotational coherences with the same learning algorithm; demonstrating selective control in room temperature molecules at atmospheric pressures. Moreover, we demonstrate that modifications to the algorithm can help automatically uncover the physics of the control mechanism found by the learning algorithm. We also demonstrate a new pulse-compression technique using rotational phase modulation, where optical pulses were compressed by an order of magnitude after phase modulation by a molecular rotational coherence and subsequent propagation through a transparent window. This technique will enable efficient pulse compression in the deep-UV. Finally, we measure the coherence of EUV light generated by high-harmonic upconversion of a femtosecond laser. In phase-matched hollow-fiber geometry, the EUV light exhibits the highest inherent spatial coherence of any source in this region of the spectrum. We use this source to demonstrate the coherent image with first table-top EUV radiation. Since this source exhibits full spatial coherence at very short wavelength, this light source represents has smallest inherent effective source-size of any light source yet created. We also demonstrate that the spectrum of an optical field can be determined by measuring the interference of a double-slit pattern.