Saturation absorption

Saturated absorption Saturated brine Saturation Saturation bonding Saturation magnetization Sauerkraut Sauflon Sauflon PW S. aureus... 

The CAT model considers passive absorption, saturable absorption, degradation, and transit in the human small intestine. However, the absorption and degradation kinetics are the only model parameters that need to be determined to estimate the fraction of dose absorbed and to simulate intestinal absorption kinetics. Degradation kinetics may be determined in vitro and absorption parameters can also be determined using human intestinal perfusion techniques [85] therefore, it may be feasible to predict intestinal absorption kinetics based on in vitro degradation and in vivo perfusion data. Nevertheless, considering the complexity of oral drug absorption, such a prediction is only an approximation. 

In both cases (i. e. emission or absorption saturation) the halfwidth of this/Lamb dip is slightly dependent on laser power but mainly determined by the interaction time of the individual molecules with the standing light wave in the cavity. This time may be limited by the finite lifetimes rb of upper or lower states, by the average time l/aup between two disturbing collisions, or by the transit time Tt of the gas molecules across the laser beam. This last limitation becomes important at low pressures of the absorbing gas and for transitions between long-lived states (see Section IV.3). 

In the introduction to this chapter we gave an intuitive explanation of the origin of nonlinear optical effects and stressed the key role played by high power lasers and coherent light beams. These two concepts are defined here. We will describe one specific characteristic of laser light, namely the absorption saturation, and finally we will discuss susceptibility and frequency conversion of light. 

Fig. 8.25 Second harmonic, 90° out of phase, absorption saturation transfer spectra of 5-InVSL spin label covalently bound to the K26 peptide.

The concept of useable potential is even more important in the case of PEC water-splitting devices. The useable potential of a PEC device must be sufficiently high to drive both half reactions in addition to the overpotential losses. This can typically require over 1.6-1.9 V. To achieve this in a single junction device, semiconductor bandgaps over 3.0 eV are typically necessary, which severely restricts optical absorption, saturated photocurrent, and therefore, STH conversion efficiency. 

Multiphoton absorption Saturable absorption Cdierent effects... 

The basic advantage of R-ion doped fiber as an amplifier medium is due both to the small core size and to the low R-ion concentration required linked with the optical confinement maintained over a great length, this leads easily to absorption saturation even at a low level of pumping (a few 100 mW). This allows 3-level amplification under continuous excitation at room temperature (Mears et al. 1986). Because several books have recently been published on this now extensive and important subject (Digonnet 1993, Desurvire 1994, Becker et al. 1996), we shall present here only a few basic features and remarks. 

Absorption. Because high pumping fluxes are easily reached at levels of about 0.2 MW cm, absorption saturation at a doping level of even 1000 ppm is readily obtained it deforms the absorption spectra in comparison with bulk results so studying a fiber, it is difficult to measure the real spectroscopic absorption coefficient and line shape of a R transition as illustrated by fig. 35 even at 50mW input level (Auzel 1993). 

Therefore, a nonresonant third-order process can be overcome by a resonantly enhanced higher order process. Strong two-photon excitation or absorption saturation at 2ct), would generate strong fifth or higher order nonlinearities. Therefore, a careful characterization of a nonlinear optical response necessitates the investigation of the possible roles of higher order nonlinearities enhanced by multiphoton resonances or saturation processes. 

The open-aperture Z-scan profile is symmetrical with respect to the focus plan (z = 0) where the transmittance is a minimum (i.e., multiphoton absorption) or a maximum (i.e., absorption saturation). The open-aperture transmittance at 532 nm from a 1-mm cell of polysilane solution is shown in Fig. 8. The dashed curve is a theoretical fit using Eq. 24 with /3 = 0.027 cm/GW. With /3 known, the Z-scan with aperture in place (5 < 1) is used to determine the coefficient y. 

Absorption saturation occurs when there is a significant filling of the conduction and valence band states available for a given photon wavelength. For InGaAs materials, for instance, this corresponds to an electron concentration in excess of 2 x lO cm and a hole concentration in excess of lO cm . ... 

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