Continuous wave models

Numerical examples are shown in Figs. 7-9. The model system used is a 2D model of H2O in a continuous wave (CW) laser field of wavelength 515nm and intensity lO W/cm. The ground electronic state X and the first excited state A are considered. The bending and rotational motions are neglected for... 

A crucial part of these experiments is the preparation of the sodium atoms into the excited state by laser optical pumping. A commercial single-mode Rhodamin 6G continuous wave (cw)-dye laser (Spectra Physics model 580) is used, having 20-40-mW single mode output power when tuned to the sodium resonance line. 

Once the mathematical formalism of theoretical matrix mechanics had been established, all players who contributed to its development, continued their collaboration, under the leadership of Niels Bohr in Copenhagen, to unravel the physical implications of the mathematical theory. This endeavour gained urgent impetus when an independent solution to the mechanics of quantum systems, based on a wave model, was published soon after by Erwin Schrodinger. A real dilemma was created when Schrodinger demonstrated the equivalence of the two approaches when defined as eigenvalue problems, despite the different philosophies which guided the development of the respective theories. The treasured assumption of matrix mechanics that only experimentally measurable observables should feature as variables of the theory clearly disqualified the unobservable wave function, which appears at the heart of wave mechanics. 

The forward and reflected electric power is measured in continuous wave (CW) mode before the exposures using a digital power meter (HP Model) and a dual directional coupler (Werlatone Model C1373). 

Constant K and the exponent a of the Mark-Houwink equation, 255 Constitutive properties, 60 Contact angle, 232 Continuous chain model, 489-90 Continuous wave NMR, 365 Contour length, 247, 490 Controllability, 800... 

G. Vishnoi, A. H. Hielscher, N. Ramanujam, and B. Chance, Photon Migration Through Fetal Head in Utero Using Continuous Wave, Near-Infrared Spectroscopy Development and Evaluation of Experimental and Numerical Models, J. Bio-med. Optics, 5(2), 163-172 (2000). 

Photo-induced reaction on a metal surface usually consists of several elementary reactions and it is difficult to model the whole reaction process. However, any reactions need to be triggered by electronic excitation. As stated in Section 20.1.4, the major mechanism is indirect excitation thus we focus on modeling the indirect excitation reaction. Since desorption from the surface is one of the simplest processes and can be a prototype for other complex surface reactions, DIET or DIME are clearly the best to study [10, 48, 53, 57, 96]. In photochemistry, continuous wave or nanosecond lasers lead to DIET, where desorption increase linearly with fluence. In contrast, the DIMET process is caused by intense and short laser pulses on the picosecond or femtosecond time scale, with nonlinear dependence on fluence. Since the fluence is proportional to the number of created hot electrons in the bulk, linear... 

The model (9.73)—(9.75) was presented as an initial value problem We were interested in the rate at which a system in state 0) decays into the continua L and R and have used the steady-state analysis as a trick. The same approach can be more directly applied to genuine steady state processes such as energy resolved (also referred to as continuous wave ) absorption and scattering. Consider, for example, the absorption lineshape problem defined by Fig. 9.4. We may identify state 0) as the photon-dressed ground state, state 1) as a zero-photon excited state and the continua R and L with the radiative and nonradiative decay channels, respectively. The interactions Fyo and correspond to radiative (e.g. dipole) coupling elements between the zero photon excited state 11 and the ground state (or other lower molecular states) dressed by one photon. The radiative quantum yield is given by the flux ratio Yr = Jq r/(Jq r Jq l) = Tis/(Fijj -F F1/,). 

Whilst the above is perfectly adequate for the description of processes observed with continuous-wave (cw) input, proper representation of the optical response to pulsed laser radiation requires one further modification to the theory. It is commonly thought difficult to represent pulses of light using quantum field theory indeed, it is impossible if a number state basis is employed. However by expressing the radiation as a product of coherent states with a definite phase relationship, it is relatively simple to construct a wavepacket to model pulsed laser radiation [39]. The physical basis for this approach is that pulses necessarily have a finite linewidth and therefore in fact entail a large number of radiation modes, so that for the pump radiation, it is appropriate to construct a coherent superposition... 

In the mid-17 " century, Isaac Newton proposed that light existed as a stream of particles, and the wave-particle debate continued for over 250 years until Planck and Einstein presented their revolutionary ideas. Give two pieces of evidence for the wave model and two for the particle model. 

A typical laser diffraction apparatus is shown in I ig-ure 34-1. The beam from a continuous-wave (CW) laser, usually a Hc-Nc laser, is collimated and passed through the sample, where scattering from particles occurs, The beam is then focused on a detector array where llic scattering pattern, shown in Figure 34-1 as a diffraction pattern, is measured, The scattering pattern is then analyzed according to theoretical models to give the particle size distribution,... 

The laser-curing experiments were performed with a continuous wave argon ion laser (Spectra Physics, Model 2000) tuned to its emission line at 363.8 ran. The radiant power at the sample position was measured to be in the range 30 K) 200 mW cm 2, depending on the selected laser output Some photopolymerization experiments were carried out with a pulsed nitrogen laser (SOPRA, mt el 804 Q which emits at a wavelength of 337.1 nm. The instantaneous radiant power was calculated to be 500 kW cm-2, based on the energy of a pulse (5 m J) and its duration (8 ns). The laser was operated in a multiple-pulse mode at a repetition rate between 2.5 and 40 Hz. An electronic shutter was used to select the desired number of pulses. 

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