Radiofrequency laser

Chr. Tamm, E. Buhr, and J. Mlynek, "Raman heterodyne studies of velocity diffusion effects in radiofrequency-laser double resonance", submitted to Phys. Rev. A. 

From the Heisenberg uncertainty principle as stated in Equation (1.16) estimate, in cm and Hz, the wavenumber and frequency spread of pulsed radiation with a pulse length of 30 fs, typical of a very short pulse from a visible laser, and of 6 ps, typical of pulsed radiofrequency radiation used in a pulsed Fourier transform NMR experiment. 

Figure 7.4 Proposals of hardware for QC. (a) Ions trapped in a radiofrequency cavity and cooled by lasers (b) molecule used to implement Shor s algorithm with NMR using...

On this subject notice that, possibly combined with various heating methods, several physical effects may be considered which allow free flotation of solid and even liquid matter. Materials may be levitated for instance by a jet of gas, by intense sound waves or by beams of laser light. Conductors levitate in strong radiofrequency fields, charged particles in alternating electric fields, magnets above superconductors or vice versa. A review on levitation in physics with the description of several techniques and their principles and applications was made by Brandt (1989). 

Ullrafine particles (UFPs) of metal and semiconductor nitrides have been synthesized by two major techniques one is the reactive gas condensation method, and the other is the chemical vapor condensation method. The former is modified from the so-called gas condensation method (or gas-evaporation method) (13), and a surrounding gas such as N2 or NII2 is used in the evaporation chamber instead of inert gases. Plasma generation has been widely adopted in order to enhance the nitridation in the particle formation process. The latter is based on the decomposition and the subsequent chemical reaction of metal chloride, carbonate, hydride, and organics used as raw materials in an appropriate reactive gas under an energetic environment formed mainly by thermal healing, radiofrequency (RF) plasma, and laser beam. Synthesis techniques are listed for every heal source for the reactive gas condensation method and for the chemical vapor condensation method in Tables 8.1.1 and 8.1.2, respectively. 

Accuracy of the radiofrequency measurements of the classic 2S — 2P Lamb shift [15, 16, 23, 24, 25] is limited by the large (about 100 MHz) natural width of the 2P state, and cannot be significantly improved. New perspectives in reducing the experimental error bars of the classic 2S — 2P Lamb shift were opened with the development of the Doppler-free two-photon laser spectroscopy for measurements of the transitions between the energy levels with different principal quantum numbers. Narrow linewidth of such transi-... 

Frontrunner blunt microdissection catheter Radiofrequency ablation with optical Coherence reflectometry guidance Laser guidewire High frequency ultrasound... 

Figure 1 Apparatus of Oxford experiment [6]. LI, L2 tunable dye lasers. UV ultra violet radiation (243 nm). RF radiofrequency dissociation of flowing molecular hydrogen. PI signal photomultiplier (Lyman-a detector). P2 photomultiplier for cavity locking and signal normalisation. SI cavity length servo-control. C conrouter. AOM acousto-optic modulator. T heated quartz cell containing tellurium. S2 laser frequency servo-control. D fast photodiode...

Nitric oxide, NO, is a chemically stable molecule and not surprisingly has been studied extensively by a range of techniques. Its microwave and far-infrared laser magnetic resonance spectra are discussed in chapter 9. These involve an understanding of both the zero-field levels and also the interactions with an external magnetic field. The pure microwave and millimetre wave spectra are described in chapter 10, but they provide information, which we will use, relevant to the radiofrequency electric resonance spectrum described in this section. 

Figure 11.41. Energy level diagrams and transitions for two different F-branch transitions in the YS molecule. The broken lines denote laser-induced fluorescence transitions, whilst the continuous lines indicate radiofrequency double resonance transitions observed in rotational levels of the ground electronic state [82].

The ground electronic state of 139La160 is X2S+ audits electronic spectrum involving the excited B2Y,1 has been studied by Doppler-free laser-induced fluorescence by Bacis, Collomb and Bessis [85] and by Bernard and Sibai [86]. Both states have therefore been well characterised and the system is ideal for radiofrequency/optical double resonance, as described by Childs, Goodman, Goodman and Young [87]. They used a collimated molecular beam, with the laser pump/probe technique described elsewhere in this chapter. 

Table 11.4. Molecular constants (in MHz) for the X2H + and B 2 + electronic states ofLaO, determined [87] from the laser/radiofrequency studies...

Figure 11.46. (a) Recording of the 21,2 <— 17,1 vibration-rotation transition of the HD+ ion, obtained by Doppler tuning the ion beam into resonance with a carbon dioxide infrared laser beam [88], (b) A radiofrequency/infrared double resonance spectrum obtained by pumping the v3 line shown in the infrared spectrum (see text for the assignment). 

An important development in the phase-shift technique is the use of a radiofrequency synthesizer as the driver for the Pockels cell modulator. In this way, the excitation beam can be modulated at any frequency between 1 and 200 MHz [137-139]. This approach allows use of cw lasers such as the He-Cd laser and even mode-locked lasers [139] as the excitation source. If d and M are measured at six to ten suitably spaced frequencies, least-squares curve-fitting techniques can be employed to obtain lifetimes with greatly enhanced precision. Typical data obtained by this multifrequency technique make measurement of decay times as short as 10 ps possible. Gratton and coworkers have developed other curve-fitting procedures to analyze data obtained on a multifrequency phase-shift fluorimeter. These experiments include the construction of time-resolved spectra [140], measurements of ro-... 

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