ABSTRACT
We show the possibility of a new kind of passive nonlinear-optical device: an optical power filter made of graded-index single-mode fiber (SMF) and a nonlinear medium (NLM). It is shown that, only for a particular power, the mode in the SMF matches the mode in the NLM. The transmission coefficient from the NLM to the SMF is determined, and it is shown that a laser beam with a particular power can be filtered out.
ABSTRACT
TM-polarized nonlinear modes supported by a symmetric five-layer dielectric structure consisting of a nonlinear medium of thickness theta (characterized by the diagonal dielectric tensor (1l) = (22) identical with (0), (33) = (0) + alpha|E(3)|(2), where E(3) is the TE-field component) sandwiched between two linear films of thickness beta (with dielectric constant (1)), which are bounded from the free ends by the same nonlinear medium, are analyzed. Dispersion relations and the expressions for the power flow, derived for the symmetric and antisymmetric modes, show that for a sufficiently large value of beta/lambda, where lambda is the wavelength, these modes should show bistable behavior, provided that power flow is the control parameter.
ABSTRACT
A realistic theory of propagation of pulses in optical fibers is presented. Time-bounded em pulses, when launched at the entrance aperture of the dispersive fiber, become spatially bounded as well. Following the Fourier technique, expressions for the time-delay difference and the broadening of the pulses are derived for the spatially bounded quasi-monochromatic pulses after they have traversed a known length in the fiber. The present results, when compared with the experimental observations of Smiley et al., show reasonably good agreement and there is marked improvement over the existing theoretical results.
