During the last years optical coherent nonlinear properties of
semiconductor quantum dots have been a major research topic [1]. In
particular, experimental investigations on the possibility of
optical solitons and self-induced transparency in semiconductor
quantum dot waveguides have been reported [2]. Recently, also
theoretical investigations of breathers of self-induced transparency
have been considered for plane waves in semiconductor quantum dots (SQD),
and explicit analytical expressions for the parameters of the
resonance breathers have been presented [3].
Up to now at the considerations of nonlinear waves in SQD of
existence the borders of crystals have been ignored. Taking into
account of borders of a crystal results in occurrence of surface
conditions for electrons, excitons, phonons and other
quasi-particles. For the description of surface branches of
energetic of spectrum of the
crystals it is necessary to take into account boundary
conditions. On the boundary of the division such
media the surface electromagnetic waves can be propagating .
The properties of the surface modes when one of the connected medium is
semiconductor are investigated in detail [4]. On the other
hand, in the boundary of semiconductors with another meduim, can be growing the SQD, which can form a thin transitive layer.
In this contribution, a theory of optical solitons for the nonlinear
coherent interaction of surface TM-modes with a layer of an ensemble
of inhomogeneously broadened SQD is developed. Explicit analytical
expressions for the surface soliton
(2<\pi> pulse) in the presence of single and biexciton transitions
are obtained in the regime of self-induced transparency. The
analysis shows that realistic parameters for soliton formation can
be reached in current experiments.
[1]D. Bimberg, M. Grundmann, L. Lednetsov, Quantum Dot Heterostructures
(Wiley 1999).
[2]S. Schneider, P. Borri, W. Langbein, U. Woggon, J. Forstner, A.
Knorr, R. Sellin, D. Ouyang, and D. Bimberg, Apl. Phys. Lett.,
v. 83 (2003), 3668-3671.
[3]G.T. Adamashvili and A. Knorr, Opt. Lett.,
v. 31 (2006),74-78.
[4]Sovremennie problemi nauki o kondensirovannich sred, Poverchnostnie
polaritoni, Elektromagnitnie volni na poverchnostiach i granicach
pazdela sred. Edited by V.M. Agranovich and A.A.Maradudin, Moscow,
Nauka, 1985.
|