Transmission and reflection studies of periodic and random systems with gain

Article

关键词: WEAK-LOCALIZATION;    AMPLIFYING MEDIUM;    CLASSICAL WAVES;    LIGHT;    BACKSCATTERING;    AMPLIFICATION;    ABSORPTION;    LASER;   

DOI  :  10.1103/PhysRevB.59.6159

来源: SCIE

【 摘 要 】

The transmission ((T) and reflection (R) coefficients are studied in periodic systems and random systems with gain. For both the periodic electronic tight-binding model and the periodic classical many-layered model, we obtain numerically and theoretically the dependence of T and R. The critical length of periodic system L-c(0), above which T decreases with the size of the system L while R approaches a constant value, is obtained to be inversely proportional to the imaginary part epsilon'' of the dielectric function epsilon. For the random system, T and R also show a nonmonotonic behavior versus L. For short systems (L < L-c) with gain < In T >=(l(g)(-1) -xi(0)(-1))L. For large systems (L much greater than L-c,) with gain < In T >= -(l(g)(-1)+xi(0)(-1))L. L-c, l(g), and xi(0) are the critical, gain, and localization lengths, respectively. The dependence of the critical length L-c on epsilon'' and disorder strength W are also given. Finally, the probability distribution of the reflection R for random systems with gain is also examined. Some very interesting behaviors are observed. [S0163-182(99)02809-X].

【 授权许可】

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