Absorptive optical bistability

Hui Wang, Lan Wen-guang, Lin Wei-Zhu +2 more

Based on the established theory of photoinduced exciton bleaching of the polymers with nondegenerated ground state,we calculated the transient mirrorless optical bistability of photoexcitation and relaxation processes in the polymers.The results show that the transient saturation absorption mirrorless optical bistabilities and the increasing absorption mirrorless optical bistabilities can be obtained from the ultrafast excitation and relaxation processes in the polymers with nondegenerate ground state,and the switching time of the optical bistabilities is of the order of fs or ps.With the increase of the delay time of the probe pulse relative to pump pulse,the nature of mirrorless optical bistability can change from the saturation absorption optical bistability to increasing absorption optical bistability,and the rate of change is proportional to the speed of relaxation of the photoinduced exciton.

C. M. Bowden

Redstone Arsenal

Ying Hua Ji, Fucheng Lin

The optical bistability of a four-level system with triplet-state absorption typical of organic media is studied. We derive the state equation of optical bistability with triplet-state absorption. Different bistabilities with resonant absorption or dispersion of the triplet state are numerically discussed. The effects of the cooperativity parameter and the atomic- and cavity-detuning parameters on optical bistable behavior are analyzed. It is found that the hysteresis loops decrease with an increase of both the cooperativity parameter and the atomic-detuning parameter of the triplet state and that under some conditions reverse saturable-absorptive media can display bistability.

Hui Wang

The characteristic of optical bistability switching of azobenzene molecules is discussed.First,we compute the coefficient of reverse saturable absorption based on the model of photoisomerization of azobenzene molecules.Second,we simulate and compute the process of bistability switching based on reverse saturable absorption.The result shows that the reverse saturable absorption based on photoisomerization of azobenzene molecules can realize full optical switches of bistability.We also discusse the Trans isomer σT,the Cis isomer σC and the thermal constant K to the optical bistability influence.