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1.
A strong optogalvanic effect has been observed in a negative glow of a miniature neon discharge lamp using tunable pulse dye laser pumped by a copper vapor laser. A comparative study on temporal evolution of optogalvanic signal in a positive and negative dynamic resistance region of the discharge is described. Dye laser beam was tuned to various neon transitions 1si → 2pj (Paschen notations) within 570-617 nm wavelength range. Anomalous behavior of optogalvanic signal was observed at 588.2 nm for (1s5 → 2p2) neon transition at low discharge current (<220 μA). This anomalous behavior is the attributes of damped oscillations of optogalvanic signal that correlate with negative dynamic resistance (dV/di < 0) of the discharge. Penning ionization at low discharge current and small energy mismatch is assumed to be the main cause of the negative dynamic resistance. Penning ionization process has been explained by resonantly ionizing energy transfer via collisions between neon buffer gas atoms in the lowest metastable state (1s5) and electrode sputtered atoms in ground state using their partial energy level diagram. 相似文献
2.
Summary The formation of NaNe molecule has been detected in a hollow cathode lamp containing traces of sodium and neon using the optogalvanic
technique. Two broad continuum peaks have been observed in the structure. They have been analysed to result due to transitions
{Na(3s) + Ne(2p
6)}2Σ1→ →{Na*(3p) + Ne(2p
6)}2Π,2Σ and {Na*(3p) + Ne(2p
6)}2Π,2Σ→{Na*(5s) + Ne(2p
6)}2Σ1. A third peak in between these is probably due to a two-photon transition from 3s→5s of Na in NaNe.
The authors of this paper have agreed to not receive the proofs for correction. 相似文献
3.
B. M. Landsberg 《Applied Physics A: Materials Science & Processing》1980,23(2):127-130
Two new cw submillimetre lines optically pumped by the 9 μR(30) CO2 laser have been observed for14NH3 and assigned to thea(6,0)→s(5,0) transition and to its cascade transitions(5,0)→a(4,0) in thev
2=1 state. In addition, six new emission lines have been observed for NH2D, and one tentatively assigned to the (11,1)→(10,1) transition of ND3. Methylamine has also been investigated and twenty-eight new emission lines have been discovered. 相似文献
4.
85 Rb, 5s2S1/2(F”=2)→6p2P1/2(F’=2,3) absorption resonance with the 88Sr+, 5s2S1/2→5p2P1/2 transition is exploited to provide a simple, effective frequency reference for a laser cooling/fluorescence excitation source
applied to single Sr+ ions. A modulation-free frequency stabilization system has been designed which uses the differential signal from two frequency-displaced
beams traversing a Rb cell and which probe the Doppler-broadened Rb S–P lineshape at microwatt power levels. The method is
applied to frequency lock a 422-nm frequency-doubled diode laser system that is used for excitation of a single 88Sr+ ion. Stable, long-term laser cooling and fluorescence are achieved using the frequency-stabilized 422-nm source resulting
in observed ion confinement times without adjustment of over 8 h, together with an improvement in single-ion loading efficiency.
Received: 12 February 1998 相似文献
5.
L. W. G. Steenhuijsen 《等离子体物理论文集》1981,21(5):301-328
We report on the experimental and numerical investigations on afterglows of neon gas discharges, which are performed at the Eindhoven University of Technology. The studied gas pressure range extends from 1 to 100 torr, the discharge current from 1 to 100 mA. The densities of the 1s-levels are measured with the help of the selective excitation spectroscopy (fluorescence technique). In this way a great number of decay curves of the 1s-densities have been measured in the afterglow of neon gas discharges. From these curves the diffusion coefficient of the metastable 1s-atoms, the coefficients of atomic collisional transfer between the 1s5- and 1s4-level, as well as the three body collision coefficient between metastable 1s5-atoms and neon ground state atoms have been determined. Besides these experiments a numerical model of the neon afterglows has been developed. With this model the afterglow phenomena can be simulated and the influence of the particular processes on the whole afterglow can be studied conveniently. Comparison is made between the experimentally and numerically obtained decay curves. For the application of the numerical model a number of starting conditions, such as radial density profiles, gas temperature, (relative) densities of the 1s-levels, have been measured. Results of these measurements are presented. Also with the help of the selective excitation spectroscopy the coefficients of atomic collisional transfer between the 2p-levels have been measured in the afterglow. From these results, together with the measured (relative) intensities of the neon spectral lines in the afterglow the partial recombination coefficients for the 2p-levels were calculated. 相似文献
6.
Shaukat Mahmood Nek M. Shaikh M.A. Kalyar M. Rafiq N.K. Piracha M.A. Baig 《Journal of Quantitative Spectroscopy & Radiative Transfer》2009,110(17):1840-1850
In the present work emission and absorption spectroscopy have been used to determine the plasma parameters of neon in a hollow cathode discharge lamp. The excitation temperature is determined using the intensity ratio method and Boltzmann's plot method whereas the electron density is determined from the Stark broadening of the spectral lines. The behavior of the optogalvanic signal as a function of laser energy has been studied for three transitions from the 2p53s [1/2]2 metastable state following ΔJ=ΔK=0, ±1 dipole selection rules. The saturation technique has been used to measure the photoionization cross section from three intermediate states 2p53p′ [1/2]1, 2p53p′ [3/2]2 and 2p53p [5/2]3 up to the 2p5 2P1/2 ionization threshold. 相似文献
7.
We report on an extended cavity diode laser for operation near 640 nm. The laser is continuously tunable in 10 GHz ranges with a maximum output power of 3 mW. The laser system has been constructed using off-the-shelf optoelectronic components and easily machinable mechanical parts. The constructed system has been used to study the saturated absorption of the closed 1s5–2p9 neon transition in a radio-frequency discharge that can be maintained at neon pressures down to 10−2 Pa. 相似文献
8.
Takashi Fujimoto Yasunori Uetani Yutaka Sato Chiaki Goto Kuniya Fukuda 《Optics Communications》1983,47(2):111-116
For a pulsed-laser excitation of various neon transitions (1sj → 2pk) in a glow discharge the population perturbations in the upper and lower levels are measured by emission and absorption spectroscopy, and the dynamical optogalvanic signals are observed. We propose that the population perturbation in the lower levels (1s2–1s5) as a whole is responsible for the optogalvanic signal, and that metastable-level populations determine its decay characteristics. The sign reversal of the optogalvanic signal that depends on the excitation condition is interpreted in this context. 相似文献
9.
A running light wave, resonant with the neon transition 1s5-2p2, has been found out to affect the spatial distribution of neon atoms in a positive discharge column. The effect has shown an antisymmetric dependence (typical of the light-induced drift) on the tuning out of the radiation frequency relatively the absorption line centre, as well as on the direction of the light wave vector. 相似文献
10.
R.Kh. Zhukavin D.M. Gaponova A.V. Muravjov E.E. Orlova V.N. Shastin S.G. Pavlov H.-W. Hübers J.N. Hovenier T.O. Klaassen H. Riemann A.F.G. van der Meer 《Applied physics. B, Lasers and optics》2003,76(5):613-616
Terahertz stimulated emission of phosphorus donors in silicon optically excited by radiation from the free-electron laser
FELIX has been studied. It is found that a spectral line of the Si:P laser emission depends on pump frequency. Stimulated
emission arises on the 2p0→1s(E) intra-centre transition (21.2 meV) under resonant pumping of the 2p0 state and on the 2p0→1s(T2) transition (22.3 meV) under pumping of the 2p± or higher odd-parity donor states. The line shift is attributed to the Auger redistribution of the 1s(E)- and 1s(T2)-state populations.
Received: 7 November 2002 / Revised version: 7 April 2003 / Published online: 14 May 2003
RID="*"
ID="*"Corresponding author. Fax: +49-30/6705-55-07, E-mail: sergeij.pavlov@dlr.de
RID="**"
ID="**"On leave from: The Institute for Physics of Microstructures, Nizhny Novgorod, Russia 相似文献
11.
The influence of resonances on the muon transfer processes from muonic hydrogen to oxygen and neon (pμ)1s + O8+ → p + (μO)nl7+ and (pμ)1s + Ne10+ → p + (μNe)nl9+ is considered using the Smith lifetime matrix formalism. It is shown that the existence of a long lived resonance in the
case of Ne induces a stronger dependence on collision energy of the muon transfer cross-section for this system.
Present address: Chemistry Department, Vancouver University, Vancouver, BC V6T 1Z3, Canada 相似文献
12.
J. Franzke H. D. Wizemann K. Niemax C. Vadla 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2000,8(1):23-28
The collisional broadening and shift rate coefficients of the 283.39 nm (6p
2
3P0 → 7s
3P1
o
), 364.06 nm (6p
2
3P1 → 7s
3P1
o
), 368.45 nm (6p
2
3P1 → 7s
3P0
o
) and 405.90 nm (6p
2
3P2 → 7s
3P1
o
) Pb lines by He and Ar have been measured by fitting the experimental absorption line shapes to theoretical Voigt profiles.
The absorption measurements were performed in a resistively heated, Pb loaded oven with an integrated dc noble gas discharge
to produce also Pb atoms in the 6p
2
3P1 and 6p
2
3P2 metastable states. The diffusion of the metastable atoms out of the discharge zone into the neutral noble-gas atmosphere
enabled the line-shape and shift measurement of the lines involving the metastable states without the influence of the discharge
plasma. 相似文献
13.
The trielectronic recombination of an In+ (4d
105s
2
1
S
0) ion in collisions with slow electrons, including the two-electron excitation of the 5s2 core of the ion with the simultaneous capture of the triply excited 5p
3 intermediate autoionizing state with its subsequent radiative stabilization 5p
3 → 5s5p
2 + hν has been detected and experimentally examined for the first time. The maximum effective cross section of trielectronic recombination
is 1.6 × 10−16 cm2, which is comparable to the effective cross sections for both dielectronic recombination and electron excitation of the In+ ion. 相似文献
14.
In this paper we investigate the hyperfine structure and isotope shift of four near infrared xenon transitions by means of
a semiconductor diode laser. Doppler free spectra were obtained by using either a saturation spectroscopy technique in cell
or a laser induced fluorescence technique on a collimated atomic metastable beam. The hyperfine coupling constants of 129Xe and 131Xe were determined for the levels 1s5, 1s4, 1s42, 2p2, 2p4 and 2p6 (Paschen notation). Moreover, a systematic study of the isotope shift was performed for the 1s3 → 2p4 and 1s5 → 2p6 transitions for which all the stable isotopes 128–131Xe , 132Xe, 134Xe, and 136Xe were fully resolved.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
15.
P. Babu R. Vijaya Kyoung Hyuk Jang Hyo Jin Seo V. Lavin C. K. Jayasankar 《Pramana》2010,75(5):1005-1010
A fluorophosphate laser glass doped with 1.0 mol% of Eu3+ ions has been prepared and studied by site-selective spectroscopy to explore the local structure of Eu3+ ions. Site-selective 5
D
0 → 7
F
1,2 emission spectra have been measured under resonant excitation to the 5
D
0 level at different wavelengths within the 7
F
0 → 5
D
0 band at 16 K. Using the Stark level positions of the 7
F
1 and 7
F
2 levels, crystal-field analysis has been carried out. The results suggest the existence of a unique kind of site for all the
environments of Eu3+ ions in this glass. 相似文献
16.
The optical excitation functions (OEFs) for four series of spectral lines of the Zn atom at the transitions 4sn
1
s
1
S
0 → 4s4p
1
P
1∘ (n
1 = 6–10), 4sn
2
s
3
S
1 → 4s4p
3
P
2∘ (n
2 = 6−8), 4sn
3
d
1
D
2 → 4s4p
1
P
1∘ (n
3 = 4−6), 4sn
4
d
3
D
1, 2, 3 → 4s4p
3
P
2∘ (n
4 = 4−7) excited by a monoenergetic (0.04–0.08 eV) electron beam with energies from the excitation threshold to 18–19 eV are
measured. In the energy dependences of the excitation cross sections, the effect of post-collision interaction of slow (scattered)
and fast (emitted after the autoionization state decay) electrons is observed and described. This interaction leads to the
capture of a slow electron into the listed discrete levels and the appearance of maxima in the excitation functions. The energies
of the maxima are used to determine the energies and widths of single autoionization states or their groups by approximate
formulas of the classical approach. The autoionization levels of the zinc atom responsible for the maxima observed are determined.
Possible transfer of the orbital angular momentum between electrons is analyzed. 相似文献
17.
18.
A. Schabert R. Keil P. E. Toschek 《Applied Physics A: Materials Science & Processing》1975,6(2):181-184
Cross-saturated absorption at the neon line 2s
2–2p
4 caused by the saturating line 3s
2–2p
4 has been applied to the observation of the dynamic Stark effect by 1) power broadening, due to triple-quantum and higher
multiple-quantum transitions, of the light shift contribution to the susceptibility, and 2) a direct splitting in the electronic
Raman-Stokes contribution which occurs because of the partial compensation of the Doppler broadening.
Work supported by the “Deutsche Forschungsgemeinschaft”. 相似文献
19.
André Monteil Jacques Chevaleyre Annie Bouvier Joseph Janin 《Journal of Quantitative Spectroscopy & Radiative Transfer》1977,18(6):573-580
Radiation trapping of the transition 2p1-1s2 of neon has been demonstrated during laser-induced fluorescence in a pulsed microwave discharge through neon. The population of Ne(1s2) atoms is deduced. Selective excitation is useful for the determination of lifetimes and cross sections of collisions with neutral atoms. The results may be utilized in processes for the creation of metastable atoms. 相似文献
20.
Single tracks and pairs of tracks are written in the volume of Pr-doped LiYF4-crystals using tightly focused femtosecond laser radiation (λ=1045 nm, τ
p=400–500 fs, f=0.1–1 MHz). Waveguiding between the tracks is demonstrated and optimized by varying the distance between the tracks and the
laser writing conditions. The stress-induced guiding mechanism is explained based on TEM, interference microscopy, near-field
and far-field measurements. It is shown that the single-crystalline material is getting poly-crystalline under femtosecond
laser irradiation. By measuring the lifetime of the 3P1→3H5 transition and the emission spectrum at excitation with λ=444 nm, no influence on these properties of the guided light is observed. This possibly enables the realization of a channel
waveguide laser in the visible spectral range. 相似文献