Resonance radiation, first demonstrated

Since the parallel components of the dynamic dipole are active in RAIRS, it is possible to use the azimuthal dependence to obtain the orientation of the adsorbate at the surface. A similar technique has been applied to adsorbates on metals in HREELS measurements made off specular in order to observe parallel modes through impact or resonant scattering processes. This was first demonstrated for the Rh(CO)2 molecule on anisotropic TiO2(110) surface [72]. The results of this study also allow a test of the three layer model theory (Fig.5,6) as applied to S-polarised radiation. Fig. 11 shows the FT-RAIRS spectrum for 1/3 monolayer of Rh(CO)2 on Ti02(l 10) measured with P and S polarised radiation. 

Since photons are also Bosons with spin 1ft the question arises whether a BEC can be realized with photons. Since their mass m = hv/c is much smaller than that of atoms, BEC should start already at much higher temperatures according to Eq. (9.46). However, because there exist no photons at rest a photon condensate has to be defined in another way, namely as an ensemble of non-distinguishable photons, which are all in the same quantum state, i.e. in the same mode of the radiation field inside a resonator with a high Q-value. A first demonstration of such a photon condensate inside an optical micro-resonator was published by Weitz and coworkers in Bonn [1188],... 

Demonstration of levitation of micron-sized latex particles by radiation pressure dates back to 1970 in the experiments reported by Ashkin [Ashkin 1970]. The average force accelerating (or slowing down) atoms in a laser field was derived by A.Kazantsev in 1972 [Kazantsev 1974]. Later in 1972-1974 he classified the optical forces as spontaneous, induced and mixed. In particular, it was he who first presented the dipole potentials for velocity broadened lines of resonance atoms in the logarithmic form... 

If the measurements of the intensity of radiation from excited species are to be related to the concentration of ground state species, it is necessary to demonstrate that the species are in thermal equilibrium so that equation (3.33) may be apphed. This may be done by three methods. In the first place, the determination of flame temperature by the line reversal technique demands that there be thermal equilibration, and the concordance of a temperature so determined with that determined by other methods, or from lines known to be equilibrated is evidence for equilibration. Secondly the comparison of measured intensities of the first and higher resonance lines should be in accord with (3.33), a comparison which may be extended to a pair of different atoms if compound formation is not important. Thirdly, and most commonly, (3.33) may be transformed into... 

Obviously, any medium used for generating radiation at wavelengths below 200 nm must be transparent to such radiation. This condition is generally met by the rare gases and some metal vapors. New and Ward [21] were the first to demonstrate THG in gases. Subsequently, Harris and Miles [22] showed that relatively high conversion efficiency of THG and 4-WSM could be obtained by using phase-matched metal vapors as nonlinear media, and that efficiency could be improved further by resonance enhancement. 

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