scispace - formally typeset
Search or ask a question

Showing papers on "Stark effect published in 1984"


Journal ArticleDOI
TL;DR: In this article, the authors present theory and extended experimental results for the large shift in optical absorption in GaAs-AlGaAs quantum well structures with electric field perpendicular to the layers.
Abstract: We present theory and extended experimental results for the large shift in optical absorption in GaAs-AlGaAs quantum well structures with electric field perpendicular to the layers. In contrast to the Stark effect on atoms or on excitons in bulk semiconductors, the exciton resonances remain resolved even for shifts much larger than the zero-field binding energy and fields g 50 times the classical ionization field. The model explains these results as a consequence of the quantum confinement of carriers.

1,604 citations


Journal ArticleDOI
David K. Lambert1
TL;DR: The theory of the vibrational Stark effect of adsorbates is discussed in this paper, where the reported linear variation of CO vibrational frequency with potential difference across the Pt-electrolyte interface is shown to be consistent with a recent measurement of the Stark tuning rate of CO on Ni in UHV and the differential capacitance of the Pt electrode interface.

149 citations


Journal ArticleDOI
TL;DR: A critical review of all experimental data on Stark widths and shifts of spectral lines of neutral elements published during the period 1976-1982 has been carried out as mentioned in this paper, which represents an extension and update of an earlier review which covered the period before 1976.
Abstract: A critical review of all experimental data on Stark widths and shifts of spectral lines of neutral elements published during the period 1976–1982 has been carried out. This work represents an extension and update of an earlier review which covered the period before 1976. Data tables containing the selected experimental Stark broadening parameters are presented together with estimated accuracies. Comparisons with comprehensive calculations based on the semiclassical theory are made whenever possible.

129 citations


Journal ArticleDOI
TL;DR: In this article, a semiclassical approach has been used to evaluate Stark broadening of atomic lines and also electron-and proton-impact line widths and shifts of 30 neutral sodium lines.
Abstract: A semiclassical approach has been used to evaluate Stark broadening of atomic lines and also electron-and proton-impact line widths and shifts of 30 neutral sodium lines. The results are used to investigate Stark broadening-parameter regularities within the spectral series.

115 citations


Journal ArticleDOI
TL;DR: In this article, the authors used optogalvanic detection of He Rydberg atoms in the cathode fall region of a glow discharge to measure the strength of discharge electric fields.
Abstract: Spatially resolved electric field measurements in the cathode fall region of a glow discharge are performed using optogalvanic detection of He Rydberg atoms. The large linear Stark effect of Rydberg levels provides an accurate, sensitive measure of discharge electric fields.

94 citations


Journal ArticleDOI
TL;DR: In this paper, a critical review of the available experimental data on the Stark widths and shifts for lines of non-hydrogenic ionized spectra has been carried out which covers the period from 1976 to the present and represents a continuation of an earlier critical review.
Abstract: A new critical review of the available experimental data on the Stark widths and shifts for lines of non‐hydrogenic ionized spectra has been carried out which covers the period from 1976 to the present and represents a continuation of an earlier critical review. The relevant literature, compiled by the NBS Data Center on Atomic Lines Shapes and Shifts as well as by the present authors, was critically evaluated, and data tables containing the selected experimental Stark broadening parameters have been assembled. The data are arranged according to spectra and elements and these are presented in alphabetical order. The accuracy of the experimental data is estimated on the basis of guidelines developed during the previous review. Comparisons with theoretical results are made whenever possible since the comparison with theory has often been a principal motivation for the experiments.

85 citations


Journal ArticleDOI
TL;DR: In this article, the rotational spectrum of the weakly bound complex ArHCN has been observed using molecular beam electric resonance spectroscopy, which is superficially characteristic of a linear molecule with both unusually large centrifugal distortion (requiring a J6 dependent distortion term to fit the data) and an unexpectedly large bending amplitude.
Abstract: The rotational spectrum of the weakly bound complex ArHCN has been observed using molecular beam electric resonance spectroscopy. The spectrum is superficially characteristic of that of a linear molecule with both unusually large centrifugal distortion (requiring a J6 dependent distortion term to fit the data) and an unexpectedly large bending amplitude. The spectroscopic constants are The centrifugal distortion constant DJ is remarkably large and abnormally sensitive to isotopic substitution. Using the usual model, the stretching and bending force constants obtained from these data are an order of magnitude smaller than those similarly computed for the hydrogen halide complexes of argon. The calculated stretching and bending frequencies are 10 cm−1, predicting that excited vibrational levels should be populated in the beam. Three transitions have been observed which appear to correspond to an excited vibrational level of ArDCN, but poor signal‐to‐noise has prohibited their unambiguous assignment. W...

74 citations


Journal ArticleDOI
TL;DR: In this article, a laser-microwave double resonance (LMDR) with high electric field was applied to the OCS molecule, which was observed with CO2 and CO lasers.
Abstract: Laser–microwave double resonance (LMDR) with high electric field was applied to the OCS molecule. Stark Lamb‐dip spectra due to the infrared transitions of the 2ν2(0200–0000, 9.6 μm), 2ν1 (2000–0000, 5.8 μm), and ν1+2ν2 (1200–0000, 5.3 μm) bands were observed with the CO2 and CO lasers. The spectra due to the corresponding hot bands; 0310–0110, 0400–0200, 1200–1000, 1310–1110; 2110–0110, 3000–1000; 1400–0200, 1420–0220, 1510–0310, 2200–1000; and a few bands of OC34S and O13CS were also identified. Associated with these infrared transitions, more than 90 LMDR signals were detected and assigned to rotational transitions in the 11 vibrational states 0000, 1000, 2000, 0110, 0200, 0220, 0310, 0400, 1200, 1420, and 2200 of the normal species, and in the two vibrational states 0000 and 0200 of both OC34S and O13CS. Dipole moments were determined with accuracies (2.5σ) better than 2×10−5 D for all these vibrational states. Polarizability anisotropies were also obtained for some states. The data for the ground ν1 ...

71 citations


Journal ArticleDOI
TL;DR: In this article, the authors measured the electric dipole moment of the X 2 ε+ (v = 0) electronic ground state of CaF using a molecular beam, laser-rf, double resonance technique.
Abstract: The molecular beam, laser‐rf, double‐resonance technique has been used to measure the electric‐dipole moment of the X 2Σ+ (v=0) electronic ground state of CaF. The moment was determined to be 3.07(7) D by measuring the Stark shifts of rf transitions within specified rovibrational states of X 2Σ+.

67 citations


Journal ArticleDOI
TL;DR: In this article, a computer simulation technique is used to calculate hydrogen spectral lines emitted by a plasma and these calculations are used to study ion dynamic effects on the line profiles, and comparisons are made with experimental results and with other theoretical methods.
Abstract: A computer simulation technique is used to calculate hydrogen spectral lines emitted by a plasma. These calculations are used to study ion dynamic effects on the line profiles. Results are obtained for Lyman-$\ensuremath{\alpha}$, Layman-$\ensuremath{\beta}$, and Lyman-$\ensuremath{\gamma}$ lines, and comparisons are made with experimental results and with other theoretical methods.

62 citations


Journal ArticleDOI
TL;DR: In this paper, an electric field parallel to the polymer chain axis produces in both types of single crystals (1) a Stark shift of the main absorption peak and (2) a new absorption peak on the high energy side of main peak.

Journal ArticleDOI
A. Salin1
TL;DR: The influence of the Stark effect on the distribution of excited states produced by electron capture from atomic hydrogen into slow fully stripped ions is studied in this paper, which supports the utility of measuring the polarization of radiation emitted by decay of the excited states formed in the collision.
Abstract: The influence of the Stark effect on the l distribution of excited states produced by electron capture from atomic hydrogen into slow fully stripped ions is studied. The Stark effect is strong enough, in these monoelectronic systems, to preclude any relation between the final l distribution and the primary process of electron capture. The latter determines the m distribution through «geometrical» effects, which supports the utility of measuring the polarization of radiation emitted by decay of the excited states formed in the collision Etude theorique du role de l'effet Stark sur la distribution en l des etats excites formes par capture d'electrons dans l'hydrogene atomique par des ions lents nus (C 6+ , O 8+ , Ne 10+ ): dans ces systemes monoelectroniques, l'effet Stark est suffisamment fort pour que la distribution en l ne garde aucune trace du processus primaire de capture electronique, qui se manifeste cependant par des effets «geometriques» observables dans la distribution en m

Journal ArticleDOI
TL;DR: In this article, electric fields in the cathode fall region of a glow discharge are accurately measured in a small volume defined by the intersection of two laser beams, determined from linear Stark effects in Rydberg levels.

Journal ArticleDOI
TL;DR: In this paper, the Stark effects for radiofrequency spectra of the lowest rotational levels of the ground vibrational state of H 2 S, HDS, and D 2 S have been determined by molecular beam electric resonance spectroscopy.

Journal ArticleDOI
TL;DR: In this article, the microwave spectra of two isotopic species of hypochlorous acid, HOCl, have been measured in the frequency range 8-650 GHz to permit atmospheric monitoring of the molecule.

Journal ArticleDOI
TL;DR: In this paper, the high frequency fields generated by a relativistic electron beam plasma interaction in the BP II experiment were measured at fixed positions as well as integrated over the length of the experiment.
Abstract: Reported are measurements on the high‐frequency fields generated by a relativistic electron beam plasma interaction in the BP II experiment. Measurements are done at fixed positions as well as integrated over the length of the experiment. At fixed positions time‐resolved spectroscopy on hydrogen and helium lines is applied. The integrated measurements are performed with a magnetic energy analyzer, which measures the energy distribution of the relativistic electron beam at the end of the experiment. Spectroscopic measurements of the dynamic Stark effect and forbidden transitions lead to hf fields with amplitudes in the order of 1 MV/m. The interpretation of the beam energy spectra suggests localized fields with field strengths as great as 108 V/m.

Journal ArticleDOI
TL;DR: In this article, a computer simulation has been applied to the calculation of Stark profiles of hydrogenic ions for the conditions of inertial confinement fusion, and drastic modifications of the Lyman-line profiles are observed when ion dynamics is taken into account.
Abstract: A computer simulation has been applied to the calculation of Stark profiles of hydrogenic ions for the conditions of inertial confinement fusion. Drastic modifications of the Lyman-line profiles are observed when ion dynamics is taken into account.

Journal ArticleDOI
TL;DR: In this article, the measurement of electron density by a unique, one-parameter least-squares fit to the Stark-broadened hydrogen emission line was presented, which utilizes approximately 60-80 points and provides improved precision in the measurement.

Journal ArticleDOI
TL;DR: In this article, a simple semiclassical perturbational approach with appropriate cutoffs is sufficient to give accurate profiles in the line centre, neglecting the natural broadening and the fine-structure effects.
Abstract: Stark profiles of the H alpha lines of hydrogen are computed at low densities (from 1010 to 1013 cm-3) in the 'impact' theory. By a comparison with quantal results the authors show that a simple semiclassical perturbational approach with appropriate cutoffs is sufficient to give accurate profiles in the line centre. Neglecting the natural broadening and the fine-structure effects, they prove that the electronic broadening is negligible and that the profile has a Lorentzian shape, and they give an analytical expression of the half width.


Journal ArticleDOI
TL;DR: In this article, an analysis of sub-Doppler laser-Stark spectra of 14NH3 obtained using a CO laser and an intracavity Stark cell is given.

Journal ArticleDOI
TL;DR: In this article, a-type transition of near-symmetric prolate asymmetric top was used to determine µb or µc in two molecules, propynal and (E)-crotonaldehyde.
Abstract: Attention is drawn to the advantage of using certain selected a-type transitions of near-symmetric prolate asymmetric tops for precise determination of µb or µc in such molecules. For two such molecules, propynal and (E)-crotonaldehyde, new values of µb have been determined (Cm): propynal µb = 4.897(50) × 10-30 (E)-crotonaldehyde µb = 3.403(59) × 10-30 which are substantially different from those previously published. Some other uses of Stark-effect measurements on such selected transitions are briefly indicated.

Book ChapterDOI
01 Jan 1984
TL;DR: In this article, a comb of precise reference FIR frequencies from 245 GHz to 8 THz, using a single CO2 laser source, is presented. But the results are limited to the case of 98 FIR lines.
Abstract: Methyl alcohol illustrates in a remarkable way the potential of the optical pumping technique. It was recognized early as a source of strong FIR lasing by Chang et al. (1970). Since then, hundreds of lines have been generated by the various isotopic modifications of the molecule. At the present time, normal CH3OH has generated more than 300 lines, ranging from 19 μm to 1223 μm, in CW or quasi-CW operation. About 200 of these lines have been pumped by conventional CO2 lasers using the normal isotopic modification of CO2 (Tables la and II). Information on wavelength, relative polarization, relative power, and pressure is generally available. Also, precise FIR frequency measurements are at our disposal for 98 FIR lines (Petersen et al., 1980 and unpublished). This is helpful for the assignment of the lines and provides a comb of precise reference FIR frequencies from 245 GHz to 8 THz, using a single laser source.

Journal ArticleDOI
15 Sep 1984
TL;DR: In this article, the second-order Stark effect in 1 Σ states of heteronuclear diatomic molecules is thoroughly reviewed and the rigorous treatment given demonstrates that by introducing rotational, vibrational and electronic branch polarizabilities, the intrinsic character of the second order Stark effect can be related more closely to polarizability than to dipole moments.
Abstract: The theory of second-order Stark effect in 1 Σ states of heteronuclear diatomic molecules is thoroughly reviewed. The rigorous treatment given demonstrates that by introducing rotational, vibrational and electronic branch polarizabilities, the intrinsic character of the second-order Stark effect in diatomic molecules can be shown to be related more closely to polarizabilities than to dipole moments. The well-known expression for the Stark shift in 1 Σ levels which is dominated by the square of the dipole moment is only a crude, though sufficient approximation whenever large dipole moments are involved. For small dipole moments, however, this approximation is likely to fail, leading to an erroneous determination of such dipole moments. In the limiting case of negligible influence of the molecular rotation on the vibronic matrix elements, the arithmetic mean of the electronic branch polarizabilities turns out to be equal to the well-known static electronic polarizabilities α ∥ and α ⊥ . The results are applied to the interpretation of the Stark splitting in the A 1 Σ + , υ′ = 5, J ′ = 1 level of 7 LiH, recently determined by Stark quantum-beat spectroscopy.

Journal ArticleDOI
TL;DR: In this article, the authors observe the Stark effect in hydrogen by photoionizing a relativistic hydrogen beam prepared by photodetachment of the 800-MeV H/sup -/ beam at the Clinton P. Anderson Meson Physics Facility.
Abstract: We observe the Stark effect in hydrogen by photoionizing a relativistic hydrogen beam prepared by photodetachment of the 800-MeV H/sup -/ beam at the Clinton P. Anderson Meson Physics Facility. Photoexcitation of H/sup 0/ is performed in a magnetic field (up to 6.5 kG) that appears in the atomic frame as an electric field up to 3 MV/cm. Resonances observed with an angle Doppler-tuned laser beam match calculated energies. At sufficiently high field, near the Stark-Coulomb potential-barrier peak, we observe shape resonances with an apparent elevation of the baseline on the high-energy side.

Journal ArticleDOI
TL;DR: In this paper, the ground state energies of the anharmonic oscillator and of the spherical Stark effect are calculated with great accuracy in the whole range of values of the coupling constant.

Journal ArticleDOI
TL;DR: In this paper, a quantitative analysis of two sets of excited states of hydrogen atom in an arbitrary constant magnetic field is carried out for the first time, and a nonlinearisation method was used.
Abstract: A quantitative analysis of two sets of excited states of hydrogen atom in an arbitrary constant magnetic field is carried out for the first time. A 'nonlinearisation' method was used. Perturbational terms up to H6 are calculated. It is shown that the domain of applicability of the perturbation theory is contracted sharply with increase in the atom excitation degree. The range of this domain is estimated. Functional structure of arbitrary correction to the wavefunction is investigated and some of its substructures are found explicitly. Detailed calculations are performed for magnetic fields of arbitrary strengths. The accuracy of the calculations is estimated. Crossovers of the levels in the region of fields >or approximately=108 G are discussed. Possible experimental consequences are considered.

Journal ArticleDOI
TL;DR: In this paper, the authors measured detailed profiles of plasma-broadened neutral-carbon lines, utilizing a wall-stabilized arc source and a specially designed data acquisition and processing system.
Abstract: We have measured detailed profiles of plasma-broadened neutral-carbon lines, utilizing a wall-stabilized arc source and a specially designed data acquisition and processing system. We analyzed the lines in terms of symmetric Lorentzian profiles in order to isolate the deviations due to asymmetries and found regular patterns of an antisymmetric nature around the line centers. The asymmetry patterns have a common shape with a minimum, maximum, and zero crossing at the same points on a reduced wavelength scale, but they vary widely in their amplitudes. These findings are in excellent qualitative agreement with the quasistatic theory of ion broadening due to the quadratic Stark effect. A comparison and match of experimental and theoretical amplitudes has thus been used to determine the ion broadening parameters of these lines, which are in satisfactory agreement with directly calculated values.

Journal ArticleDOI
TL;DR: In this article, the Stark effect of 31 levels of the neon atom was investigated by measurements of the splittings and shifts of 141 Ne I-lines in the visible region using field strengths of up to about 1200 kV cm-1.
Abstract: The Stark effect of 31 levels of the neon atom was investigated by measurements of the splittings and shifts of 141 Ne I-lines in the visible region using field strengths of up to about 1200 kV cm-1. The results are given in form of tabulated coefficients obtained by analytical approximation of the field strength dependence of the shifts.

Journal ArticleDOI
TL;DR: In this paper, the radiative lifetimes in the doubly excited 4p2 configuration in Ca were determined using the delayed coincidence technique, and the measured states were populated either with two-step laser excitation from the 4s2 1S0 ground state or with single-step excitation starting from a metastable state.
Abstract: The radiative lifetimes in the doubly excited 4p2 configuration in Ca were determined using the delayed coincidence technique. The measured states were populated either with two-step laser excitation from the 4s2 1S0 ground state or with single-step excitation starting from a metastable state. The metastable states were populated by collisions in a discharge. The following lifetime values were obtained: τ(4p2 1D2) = 16.3(20) ns, τ(4p2 1S0) = 14.4(7) ns and τ(4p2 3P0,1,2) = 6.9(4) ns. Stark shift parameters in the same configuration were measured using an atomic beam passing between electric field plates. The following results were obtained: α0(4p2 1S0) = -32.2(16) MHz (cm/kV)2, α0(4p2 1D2) = 1.8(2) MHz (cm/kV)2 and α2(4p2 1D2) = 1.15(10) MHz (cm/kV)2. Additional measurements yielded τ(4s5f1F3) = 60(3) ns, τ(4s4d3D1,2,3) = 13.0(5) ns and α0 (4s6s 1S0) = 6.98(35) MHz (cm/kV)2.