Localization in a disordered multi-mode waveguide with absorption or amplification

✍ Scribed by T.Sh. Misirpashaev; J.C.J. Paasschens; C.W.J. Beenakker

• Book ID: 104341450
• Publisher: Elsevier Science
• Year: 1997
• Tongue: English
• Weight: 617 KB
• Volume: 236
• Category: Article
• ISSN: 0378-4371
• DOI: 10.1016/s0378-4371(96)00387-1

✦ Synopsis

An analytical and numerical study of transmission of radiation through a multi-mode waveguide containing a random medium with a complex dielectric constant ~ = ~' + it" is presented. Depending on the sign of E", the medium is absorbing or amplifying. The transmitted intensity decays exponentially c< exp(-L/~) as the waveguide length L --~ c~, regardless of the sign of e". The localization length ¢ is computed as a function of the mean free path l, the absorption or amplification length la[ -1, and the number of modes in the waveguide N. The method used is an extension of the Fokker-Planck approach of Dorokhov, Mello, Pereyra and Kumar to nonunitary scattering matrices. Asymptotically exact results are obtained for N>> 1 and lal >> 1IN 2l. An approximate interpolation formula for all a agrees reasonably well with numerical simulations.