Spectrum Stark

Figure 9.24 Laser Stark spectrum of FNO showing Lamb dips in the components of the line of the ij vibrational transition. (Reproduced, with permission, from Allegrini, M., Johns, J. W. C. and McKellar, A. R. W., J. Molec. Spectrosc., 73, 168, 1978)...

Figure 9.24 shows part of the laser Stark spectrum of the bent triatomic molecule FNO obtained with a CO infrared laser operating at 1837.430 cm All the transitions shown are Stark components of the rotational line of the Ig vibrational transition, where Vj is the N-F stretching vibration. The rotational symbolism is that for a symmetric rotor (to which FNO approximates) for which q implies that AA = 0, P implies that A/ = — 1 and the numbers indicate that K" = 7 and J" = 8 (see Section 6.2.4.2). In an electric field each J level is split into (J + 1) components (see Section 5.2.3), each specified by its value of Mj. The selection mle when the radiation is polarized perpendicular to the field (as here) is AMj = 1. Eight of the resulting Stark components are shown. 

Figure 7 shows the quadratic Stark spectrum of a poly(methyl metacrylate) film doped with a azobenzene-linked amphiphile, 4-octadecyloxy-4 -nitroazobenzene. Using eq. (5) and the most characteristic spectral point on the AT/T curves, where dD/dX = 0 and d2D/dXa = 0, the value of Ap was evaluated to be 5.4 debye. Further, the p value of the azobenzene-linked amphiphile was calculated to be 24 x 10 30 esu at a fundamental wavelength of 1064 nm. The p values of azobenzene-linked amphiphiles employed in this study were evaluated by the procedure mentioned here. The values are listed in Table 2 in the section 1.1.1. 

A combination of both methods was realized by Uehara et al. 85,88) They investigated the Stark spectrum of polyatomic molecules in strong electric fields by probing the different Stark components with the Zeeman-tuned laser line. Since the molecular constants of the vibrational ground state are often known from microwave investiga-... 

By modulating the electric field and using phase-sensitive detection methods, Uehara et al. 8 ) were able to increase the sensitivity considerably and they could even detect Stark splittings of less than the doppler width of the components. Fig. 3 shows the Stark spectrum of HDCO for different electric field strengths. Because of the Stark modulation technique the absorption lines appear differentiated the zero points represent the center of each line. 

Fig. 15. Lamb dip spectroscopy of Left side Stark spectrum (with...

The method used in these calculations is based on the theoretical developments of Sakimoto [42] and is also an extension of our previous work on the Stark spectrum of spin-orbit autoionized Rydberg states of argon [43] and of the vibrationally autoionized states of hydrogen [44, 45], Only the homoge-... 

Vibrational product state distributions have been obtained for reactions studied in crossed molecular beams using the technique of beam electric resonance spectroscopy [109]. This method uses the focusing action of electric quadrupole and dipole fields to measure the radio frequency Stark spectrum of the reaction products, which must possess a dipole moment. This has restricted this technique to reactions producing alkali halides. 

Fig. III.6. The longitudinal drop of the magnetic field towards the ends of the magnet limits the usable gap volume. In the AM = 0 absorption cells used in connection with the 3 cm gap, the Stark spectrum which determines the effectively absorption cell starts 35 cm inside the magnet. The remaining inhomogeneity is accounted for in the numerical analysis...

Three infrared-infrared double resonance signals were observed in the Stark spectrum of PD3 for the v=15-14, P(20) line of the CO laser. They are caused by the accidentally overlapped Ri(2) transition in the V3 band and the R2(3) transition in the 2V3-V3 band [2]. 

Fig.2 Laser Stark spectrum of the branches of the V2 band of H2CO obtained with the 14 13P(16) line of the CO laser at 1746.307 cm . (Reproduced by permission from Journal of Molecular Spectroscopy, 1973, 4, 364.)...

Fig. 5 Intractivity laser Stark spectrum of the V3 band of HNO recorded with the 24-23 (P(16) line of a CO laser and parallel polarization. (Reproduced by permission from Journal of Chemical Physics, 1977, 6. 1220.)...

Figure 1.50 illustrates the obtainable sensitivity by a AM = 0 Stark spectrum of the ammonia isotope NH2D composed of measurements with several laser lines [146]. An electric resonance signal is observed at every crossing point of the sloped energy levels with a fixed laser frequency. Since the absolute frequency of many laser lines was measured accurately within 20 0 kHz (Sect. 9.7), the absolute frequency of the Stark components at resonance with the laser line can be measured with the same accuracy. The total accuracy in the determination of the molecular parameters is therefore mainly limited by the accuracy of 10 for the electric field measurements. To date numerous molecules have been measured with laser Stark spectroscopy [146-149]. The number of molecules accessible to this technique can be vastly enlarged if tunable lasers in the relevant spectral regions... 

Mart AJ, Flores ME, Steimle TC (1996) The optical and optical/Stark spectrum of iridium monocarbide and mononitride. J Chem Phys 104 8183-8196... 

The multiplet splitting is qualitatively determined by the point symmetry of a crystal field acting on an R ion, and the numerical characteristics of the Stark spectrum may be... 

Taking proper account of static structure deformations and the corresponding change in the Stark spectrum upon implanting an impurity ion permits qualitative and, to a certain extent, quantitative explanation of all peculiarities observed by Mehran et al. (1977, 1982, 1983) in the temperature dependence of the EPR linewidth for impurity Gd ions in Ian-... 

The diatomic yttrium halides have been the topic of both ab initio and experimental studies. Fischell et al. (1980) have studied the excitation spectra of the YCl diatomic molecule using the laser-induced fluorescence (LIF) method. More recently, Xin et al. (1991) have studied the B ri-X system of YCl in high resolution. The rotational analysis of the observed bands has yielded very accurate molecular constants for the X and B states of YCl. Shirley et al. (1990) have studied the molecular-beam optical Stark spectrum of the B n(t = 0)-X (t = 0) band system of YF. The permanent dipole moment and the magnetic hyperfine parameter a for the B n state have been determined as 2.96(4) D and 146.8(3) MHz, respectively. The dipole moment of the X S state was determined as 1.82(8)D. More recently, Shirley et al. (1991) have employed the molecular-beam millimeter-wave optical pump-probe spectroscopy to study pure rotational transitions of the YF ground state. This study has yielded improved ground-state rotational constants as B = 8683.65(1) MHz and D = 0.0079(2)-MHz, respectively. 

The Stark spectrum for the same transition at E = 26.04 kV cm"i is shown in Figure 6. Here again, the splitting is clearly seen thanks to the Doppler-free technique applied here. 

In the case of the Zeeman (Stark) splitting, the Zeeman (or Stark) spectrum is reproduced in a Fourier transform of the time dependence in the fluorescence similar to Equation [4]. It is essential that the time response of the detection system is fast enough to observe oscillations with the characteristic period 2jt/h 2i-... 

Fig.l. Stark spectrum of Rb. capsulatus, wild type (dashed line) and Dll niutant (solid line), at 77K in the Qy absorption bands. External electric field for both samples 9 lO V/cm. 

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