two-photon absorption


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two-photon absorption

[‚tü¦fō‚tän əb′sȯrp·shən]
(physical chemistry)
A relatively weak photon absorption and excitation process that occurs when a sufficiently intense light source, such as a laser beam, is used, making it possible for a molecule to absorb simultaneously two photons, each of approximately half the energy (twice the wavelength) normally required to reach an excited state. The probability of a molecule absorbing two photons simultaneously is proportional to the square of the intensity of the input beam.
References in periodicals archive ?
Solidification is performed in a highly localized volume because of the quadratic dependence of the two-photon absorption probability on the laser intensity.
Importantly, in order to increase even further the potential of the PSs presented in this project, I propose to also excite them via simultaneous two-photon absorption (TPA) in the so-called two-photon excitation PDT (2 PE-PDT).
o] for the thiophene oligomers, where they attributed to saturation of instantaneous two-photon absorption.
Previously, efforts to create a silicon laser were thwarted by two-photon absorption which hindered the light amplification.
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