Steady-state operation modes of reversible multiphoton photochemical shuttersстатья
Информация о цитировании статьи получена из
Web of Science,
Scopus
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 10 февраля 2016 г.
Аннотация:Steady-state modes of light propagation in the medium capable of absorbing n photons (where n is an arbitrary number, n ≥2) are analyzed in terms of dimensionless variables (optical thickness x, light intensity expressed in terms of a saturation flow, transmission of a light beam through a medium T≡ α/α0, and light intensity at the inlet α0), following a phenomenological approach. It is shown that in the event of multiphoton absorption, a set of transmission curves T(x, α0 is a parameter) is always bounded below by an extreme curve - the locus of the minimum T values T(x)=Tmin below which T never sinks at x=const and any α0 value. It is established that the set of T(x) curves is actually a union of two families corresponding to α0 < A and α0 > A, respectively, and separated by a separatrix with α0=A=(n-1)1/n. The curves of the first family neither touch the extreme curve nor intersect one another. The curves of the other family, on the contrary, touch the extreme curve at a single point x*(α0) and intersect one another and the curves of the first family. It is this behavior of T(x, α0) curves that imparts special service properties to multiphoton shutters in either of the two operation modes, the mode of transmission screening (at α0 < α*) and the mode of transmission enhancement (at α0 > α*). The conditions are formulated, under which a medium with truly multiphoton absorption becomes an efficient limiter bringing light beams to the desired level of intensity. A comparative analysis of the efficiency of optical shutters operated by one-photon and multiphoton absorption is carried out; it has revealed that in order to screen light beams causing bleaching upon one-photon absorption, it is expedient to use shutters with multiphoton absorption, having almost the same optical thickness.