It is shown that asymmetric waveguides with gain and loss can support a stable propagation of optical beams. This means that the propagation constants of modes of the corresponding complex optical potential are real. A class of such waveguides is found from a relation between two spectral problems. A particular example of an asymmetric waveguide, described by the hyperbolic functions, is analyzed. The existence and stability of linear modes and of continuous families of nonlinear modes are demonstrated.
© 2014 Optical Society of America
Original Manuscript: March 24, 2014
Revised Manuscript: June 9, 2014
Manuscript Accepted: June 9, 2014
Published: July 11, 2014
Eduard N. Tsoy, Izzat M. Allayarov, and Fatkhulla Kh. Abdullaev, "Stable localized modes in asymmetric waveguides with gain and loss," Opt. Lett. 39, 4215-4218 (2014)