Dispersion bandwidth

When the silver nanocrystals are organized in a 2D superlattice, the plasmon peak is shifted toward an energy lower than that obtained in solution (Fig. 6). The covered support is washed with hexane, and the nanoparticles are dispersed again in the solvent. The absorption spectrum of the latter solution is similar to that used to cover the support (free particles in hexane). This clearly indicates that the shift in the absorption spectrum of nanosized silver particles is due to their self-organization on the support. The bandwidth of the plasmon peak (1.3 eV) obtained after deposition is larger than that in solution (0.9 eV). This can be attributed to a change in the dielectric constant of the composite medium. Similar behavior is observed for various nanocrystal sizes (from 3 to 8 nm). 

When I calculated the estimated amount interval from only the response dispersion for the data using Kurtz methods, there was a substantial reduction in the amount bandwidth from the total bandwidth. This calculation was done by intersecting the bounds of the response dispersion with the linear regressed line and projecting these points to the amount axis. This reduction, however, was not nearly enough to account for differences from Wegscheider s calculation to the others. In Table IV the data is... 

Table IV. Comparison of Overall and Response Dispersion portions of Amount Bandwidths of the Transformed Method (Kurtz, et al.) with Bandwidths of the Spline Method (Wegscheider) for Dataset B.

A broad temperature acceptance bandwidth of AT 30 °C (FWHM) centered at 18 °C easily permitted room-temperature operation. The characterization of fundamental pulses entering (zlr 170 fs zlv zlr 0.32) and leaving (zlr 195 fs zlv Zlr 0.37) illustrated that these pulses were dispersed only slightly on propagation through the waveguide. 

The frequency sweep resulting from a linearly varying GD(v) of the pulse in Figure 7.4c is called a chirp. This pulse is much longer that the respective 20 fs FTL pulse of the same bandwidth (Figure 7.4b). As any optical material shows dispersion... 

Influence of Laser Bandwidth and Effective Pulse Duration on Nonlinear Signal Intensity, Showing the Dramatic Effect of Dispersion on Ultrashort Pulses... 

FIGURE 8.1 Time-domain effects of the second- and third-order dispersion. A TL pulse is one that is as short as possible given the available bandwidth. GDD causes time separation between different wavelengths of the pulse, and this broadens its duration. Third-order dispersion breaks the laser pulse into different sub-pulses in the time domain. 

We have identified high-order dispersion as the main reason why ultrashort, 10 fs, pulses have rarely been used for nonlinear optical imaging. We discussed the MllPS method for automated measurement and elimination of high-order dispersion. We provided quantitative analysis for the advantage of high-order dispersion as compared with correction limited to SOD. This enhancement was confirmed experimentally in fixed and living cells, as well as in depth imaging. Finally, we demonstrated that the broad bandwidth of ultrashort pulses can be used for selective two-photon excitation when appropriate phase or amplitude modulation is used. 

Narrow bands arise when the overlap of the atomic wave functions is small (as for 5 f s). In this case, the dispersion E(k) is strongly reduced and the bandwidth W becomes very small (zero, in the case of no overlap). The electron charge density, caused by these wave functions, is high in the core region of Fig. 12, and the quasi-particles spend most of their life there, nearly bound to the atom. In case the charge density is all confined within the core region (as for 4f in lanthanides), then the bond description loses its meaning and the atomic description holds. 

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