منابع مشابه
Two-step four-photon absorption.
We report a theoretical investigation of effective four-photon absorption (4PA) process and propose a two-step 4PA model of three-photon- induced excited-state absorption (ESA). Based on three-level rate-equation theory, we find an analytical result for the effective 4PA coefficient that depends on the three-photon absorption (3PA) cross-section, excited-state photophysical properties, and lase...
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By monitoring the nonlinear absorption of picosecond laser pulses as a function of lattice temperature, we identify four-photon absorption in bulk InAs. Optical bandgap scaling of this process is consistent with a calculation obtained from fourth-order perturbation theory for allowed–allowed–allowed–forbidden transitions. A model of nonlinear absorption based on laser-induced impact ionization ...
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A treatment of nuclear vibrational motions in two-photon absorption is laid out in detail. Perturbation theory is used to develop working formulas for diatomic molecules and tested for the X S – A P transition of carbon monoxide. The results are compared with the exact numerical values. Certain vibrational contributions, not previously recognized, are found to make an important contribution to ...
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We study the porphyrin S1 ! S0 fluorescence and the photosensitized singlet oxygen Dg ! Rg phosphorescence, both originating from absorption of photons with energy less than the porphyrin S0 ! S1 transition energy. By measuring the excitation intensity dependence of fluorescence at lowered sample temperatures, we are able to discriminate between two parallel processes of one-photon hot-band abs...
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ژورنال
عنوان ژورنال: Optics Express
سال: 2008
ISSN: 1094-4087
DOI: 10.1364/oe.16.010208