Saturated spectroscopy

Yasuda A, Yoshizawa M, Kobayashi T (1993) Fluorescence spectrum of a blue-phase polydiacetylene obtained by probe saturation spectroscopy. Chem Phys Lett 209 281-286... 

The imaginary components of the third-order nonlinear susceptibility of palladium and iridium complexes of C6o and C70 were determined using saturation spectroscopy. In all cases, ImQ ) values are smaller than those of uncomplexed C60 (1.78 X 10 16 m2 V-2) or C70 (7.55 X 10 17 m2 V-2), a result explained by decreased conjugation in the molecule and consequent decreased electron delocalization, although differing photodynamics were not excluded. 

Historical Development. Saturation spectroscopy in flame systems dates back only to about 1972. The important early work... 

Figure 23. Schematic of the two-level model used to treat saturation spectroscopy data. See the text for details.

This Doppler width can be avoided by typical sub-Doppler laser spectroscopy techniques. Laser saturation spectroscopy with a resolution close to the natural line width was used for a test of Special Relativity at the ESR. For such sub-Doppler resolution one must also take into account the small additional broadening and shift arising from the angle 0 between laser beam and ion beam in the Doppler formula. At an interaction length of 10 meters and more, angles are easily controlled to be better than 1 mrad. This limits a possible shift, which enters by... 

T. W. Hansch, I. S. Shahin, and A. L. Schawlow, Optical Resolution of the Lamb Shift in Atomic Hydrogen by Laser Saturation Spectroscopy, Nature Physical Science 235, 63-65 (1972). 

T. W. Hansch, M. H. Nayfeh, S. A. Lee, S. M. Curry, and I. S. Shahin, Precision Measurement of the Rydberg Constant by Laser Saturation Spectroscopy of the Bahner a Line in Hydrogen and Deuterium, Physical Review Letters 32, 1336-1340 (1974). 

Oscillator strengths or absorption cross sections may be obtained by applying saturation spectroscopy techniques to multistep photoionization spectroscopy. A few transitions in uranium have been studied.One of the advantages of saturation spectroscopy is that it can be applied to any one of the steps in the schemes shown in Fig. 2. The disadvantages are that the experimental requirements are severe (laser-atomic beam interaction area,-frequency,-band width and-polarization) and interpertation of the data can be complex. A detailed discussion will not be given because little application has been made to the lanthanides and actinides. We will discuss in the Autoionization section the determination of photoionization cross sections by a saturation method. 

Beside the purely spectroscopic part there has also been important development of active optical components such as electro-optic and acousto-optic modulators. Such components allowed the use of modulation schemes earlier used in the microwave region to be used in optical spectroscopy. In the early 80 s the FM-sideband technique both for stabilisation to molecular lines as well as to passive cavities were demonstrated [45,46]. The developing field of non-linear optics and the wave-mixing picture established a framework in which line shapes of different modulation schemes in saturation spectroscopy could be understood [47, 45, 46, 48,49]. 

Raj R. K., Bloch D., Snyder J. J., Camy G. and Ducloy M., High-Frequency Optically Heterodyned Saturation Spectroscopy Via Resonant Degenerate Four-Wave Mixing , Phys. Rev. Lett. Vol. 44, 1980, pp. 1251-1254. 

Shirley J. H., Modulation transfer processes in optical heterodyne saturation spectroscopy . Opt. Lett., Vol. 7,1982, pp. 537-539. 

The dephasing time, T2, can be measured by the photon echo technique or determined from the homogeneous width of saturation spectroscopy, which is a Fourier transform of the former, as easily seen from Eq. (5.35). When a sample is irradiated with three consecutive laser pulses at times, 0, t2, and f3, an echo pulse is emitted at time, t2 + t. This is called stimulated photon echo. Several additional echo techniques have been proposed. 

Picosecond absorption spectroscopy has been employed to follow the time-dependence of the optical absorption during the formation of e, while pulsed-laser saturation spectroscopy has been used to examine the... 

Our present experimental arrangement for kinetic laser saturation spectroscopy with a g-switched ruby laser has been described in detail previously where it has been shown that the amplitude and temporal profile of the probe laser pulses contain the picosecond time history of the /i-level... 

Fig. 12. Schematic for laser saturation spectroscopy (LSS), showing depletion and recovery in a two-level system. Oscilloscope traces show four transmitted laser pulses at (a) low and...

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