Laser flux

In this case, thermal equilibrium is reached and internal energies (at least for large ions) follow Boltzmann distributions. Where this equilibrium lies and which actual temperature the ions thus have is not known, but when the laser fiux density is increased, the steady state is shifted towards vibrationally more highly excited ions. Or expressed in a simplified way the ion temperature depends on the laser flux density. 

Practically, the rate constants fe for the dissociation of interest are determined at different laser flux densities P (given in W i.e. different ion temperatures. 

In the estimation of the dissociation excimer laser flux, we assume that the mildly focused laser beam has a Gaussian beam profile [121]. The photodissociation laser spot size has also been checked by examining the burn spots on thermal papers at various distances from the focusing lens. The variation of the laser beam spot size with distance from the focusing lens is consistent with that predicted by the Gaussian beam profile. In the photodissociation region the ionization laser beam spot is smaller than the photodissociation laser beam spot. 

Laser ablation has been broadly applied and developed for the synthesis of diverse nanomaterials [21,22], In this approach, an incident laser pulse penetrates into the surface of the material within a certain penetration depth. Electrons are removed from the bulk and the irradiated surface is then heated up and vaporized. At a high enough laser flux, the material is converted to plasma. Consequently, the large pressure difference between the laser produced initial seed plasma and ambient atmosphere causes a rapid expansion of the plasma plume and then it cools down. The plasma species will nucleate and grow into desirable nanostructures, either on a substrate or in a cool Hquid medium [21]. 

All the intracavity laser flux cannot be extracted because the RGH laser mixture contains many absorbers at the laser wavelength. The percent contribution of the absorption channel is shown in Fig. 8. Main absorbers seem to be... 

The percent contributions of the KrF relaxation channels are shown in Fig. 10. Sixty to eighty percent of the KrF excimers can contribute to the stimulated emission as an intracavity laser flux, depending on the excitation rate. Other relaxation processes are by a slow electron, F2, Kr, and Ar. In these collisional relaxation reactions the reaction KrF + Kr forms the Kj 2F trimer, and the reaction KrF + Ar forms the ArKrF trimer. 

At low laser flux, the mateiieil is heated by the absorbed laser energy and evaporates or sublimates. At high laser flux, the material is typically converted to a plasma As a result, a supersonic jet of particles (plume) with composition similar to the composition of the material is ejected normal to the taiget surface. The plume, similar to the rocket exhaust, expands away from the taiget with a strong forward-directed velocity distribution of the different particles. The ablated species condense on the substrate placed opposite to the taiget... 

The high laser flux in the sampling volume can effectively quench the fluorescence in a few minutes (rather than a few hours, as was necessary in macro-devices). 

In the forced Rayleigh scattering technique, the diffraction lattice of the excited state is formed by the interference of the two laser fluxes. A probe laser then follows the disappearing process of this lattice [21], The disappearance process of this lattice reflects the lifetime of the excited state T and molecular diffiision D. A plane wave laser light with a wavelength X is divided into two and they cross each other at an angle q to observe the interference pattern with a period A. In the constructive interference area, the probe will be excited and the striation of the excited state can be observed. Period A of the striation is expressed as... 

Meanwhile, the excitation probability is proportional to the square of the laser flux, with virtually no excitation outside the laser focal volume. This enables precise spatial imaging in the biomedical field [67]. In this sense, silk scaffolds functionalized by two-photon materials will certainly have an unbeatable advantage in TPF bio-imaging. 

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