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21.
Superradiant transitions were observed between high lying levels in Sr. The transitions react very sensitively to an external electric field. Superradiant cascades or one transition in a superradiant branching can be suppressed. The square root of the high of a superradiant pulse decreases with the second power of the electric field strength. This behaviour can be explained by calculations.Dedicated to Prof. Dr. Herbert Welling on the occasion of his 60th birthday 相似文献
22.
23.
R. -H. Rinkleff 《Zeitschrift für Physik A Hadrons and Nuclei》1979,291(1):23-27
The tensor polarizabilities of then s n p z 3 P 1 levels of Zn and Cd were measured using optical double resonance. From the rf-resonance signals in parallel electric and magnetic fields, the following tensor polarizabilities were deduced: Zn,α ten(4s4pz 3 P 1)=1.83(8) kHz/(kV/cm)2; Cd,α ten(5s5pz 3 P 1)=1.77(8) kHz/(kV/cm)2. Theoretical values were calculated using Coulomb approximation. The results were then compared with previous theoretical and experimental values and, in addition, with values for Hg. Theoretical results obtained by a modified Sternheimer method (E.J. Robinson: J. Opt. Soc. Am.59, 782 (1969)) are in better agreement with the experimental values than the results of the Coulomb approximation calculations. 相似文献
24.
A host-guest optical sensor for the determination of aliphatic amines as exemplified by octylamine is proposed. It is based
on the reversible fluorescence enhancement of heptakis(2,6-di-O-isobutyl)-β-cyclodextrin(DOB-β-CD) hosting tetraphenylporphyrin
(TPP) immobilized in poly(vinyl chloride) (PVC) membrane by aliphatic amine extracted from aqueous phase into membrane phase.
The optimum membrane contained 1.15 wt % TPP, 6.15 wt % DOB-β-CD as sensing reagent and other membrane materials. The fluorescence
enhancement of the membrane resulted from the formation of a stable three-component complex among DOB-β-CD, TPP, and aliphatic
amines. With the optimum conditions described, the fluorescence response of the sensor to octylamine shows a good correlation
with the theoretically derived equation in the range 1.0 × 10–6 to 8.0 × 10–4 mol/L. The response characteristics including reversibility, response time, reproducibility and lifetime and selectivity
of this optical device are also discussed in detail. This sensor has also been applied for the determination of octylamine
in water samples containing interferents with satisfactory recovery.
Received: 21 November 1999 / Revised: 10 January 2000 / Accepted: 15 January 2000 相似文献
25.
B. Fechner R. -H. Rinkleff A. Steudel 《Zeitschrift für Physik D Atoms, Molecules and Clusters》1988,8(4):333-341
The quadratic Stark effect in the hyperfine structure of all levels of the configuration 4f 7(8 S)6s6p in europium I, which can be excited by electric dipole radiation from the ground state, has been investigated by laser-atomic-beam spectroscopy. From the measured shifts and splittings of the hyperfine components the scalar and tensor polarizabilities have been deduced. From the polarizabilities radial integrals for electric dipole radiation were determined by a parametric analysis. With these radial integrals theoretical values of the polarizabilities were calculated. 相似文献
26.
Tensor polarizability and tensor hyperpolarizability of the 6s19d1D2 Rydberg state of Barium were derived from Stark splittings measured by quantum beat spectroscopy. The hyperpolarizability appearing in the fourth order contribution of the perturbation expansion was expressed in spherical tensor form. Using Coulomb approximation numerical values were calculated which are in fair agreement with experimental results. 相似文献
27.
Stark splittings of 7 levels of the configurations 4f 66s6p and 4f 55d6s2 in Sm I were measured by quantum beat spectroscopy in pure electric fields, allowing the determination of tensor polarizabilities. Additionally, the lifetimes of 11 levels of these configurations were determined from time-resolved registration of the exponential decay. From these values the radial integrals I(6p,6s), I(6p,5d), and I(5d,4f) were derived by a parametric analysis. Theoretical values of tensor polarizabilities and lifetimes which were calculated using these radial integrals show good agreement with experimental data of various authors. 相似文献
28.
B. Fechner P. Kulina R. -H. Rinkleff A. Steudel 《Zeitschrift für Physik D Atoms, Molecules and Clusters》1986,1(2):145-150
The tensor polarizabilities of the 4snd 1 D 2 Ca Rydberg states fromn=5 ton=19 have been measured using quantum beat spectroscopy at very low electric field strengths. The irregular behaviour of the polarizabilities is well reproduced by Coulomb approximation calculations. Using a quantum defect analysis, the strong variations of the tensor polarizabilities of themsnd 1 D 2 states of the alkaline earth atoms Ca, Sr, and Ba can be explained. 相似文献
29.
R. -H. Rinkleff A. Steudel K. Zeiske 《Zeitschrift für Physik D Atoms, Molecules and Clusters》1991,18(1):101-105
The nonlinear level crossing technique with parallel electric and magnetic fields was used to investigate the Stark effect of six levels of the ground multiplet 4f66s2 7 F in the Sm I-spectrum. The tensor polarizabilities were deduced from the level crossing signals. The variation of the tensor polarizabilities of the levels of the ground multiplet is well reproduced by the LS coupling approximation, which gives an average value of α2(F)=?0.88(6) kHz/(kV/cm)2 for the six measured levels. The experimental results confirm the validity of the central field approximation in the ground configuration of Sm. 相似文献
30.
N. Strauß I. Ernsting S. Schiller A. Wicht P. Huke R.-H. Rinkleff 《Applied physics. B, Lasers and optics》2007,88(1):21-28
We present a simple scheme for tuneable relative frequency stabilization of lasers. A highly sensitive and accurate frequency-to-voltage
converter is used to derive an error signal from the beat note between two lasers. We analyze in detail detector noise and
drift, modulation detection bandwidth, and cross-talk from power modulation. The results indicate that sub-kHz relative linewidth
and a locking point drift on the order of 100 Hz for times scales of 1 h are achievable. The scheme can, therefore, be applied
to situations where up to now only optical PLLs could provide sufficient accuracy and precision. To demonstrate its potential
for high-resolution, high-precision spectroscopy we lock a diode laser to a fs-frequency comb and find a relative linear drift
of 314 Hz during a 2.8 h period.
PACS 42.62.Fi; 42.62.Eh 相似文献