Optimization of Bistability in Nonlinear Chalcogenide Fiber Bragg Grating for All Optical Switch and Memory Applications

Abstract

ABSTRACT-We solve the coupled mode equations governing the chalcogenide nonlinear fiber Bragg gratings (FBGs) numerically, and obtain the bistability characteristics. The characteristics of the chalcogenide nonlinear FBGs such as: switching threshold intensity, bistability interval and on-off switching ratio are studied. The effects of FBG length and its third order nonlinear refractive index on FBG characteristics are investigated. We obtain an interesting result that independent of the third order nonlinear refractive index; there exists an optimum FBG length of about 6 mm at which the on-off switching ratio becomes maximized. It is also found that by increasing the nonlinearity, the maximum value of on-off switching ratio decreases. The results of this paper can be mainly used for designing alloptical switches and memories.

All-Optical Ternary Stability in Uniform Nonlinear Chalcogenide Fiber Bragg Gratings

“…Their various applications are known in the linear optical communication systems such as pulse dispersion compensation [1], optical filters [2], wavelength division multiplexing (WDM), optical limiters [3], and optical sensors [4]. They are also well-regarded for their nonlinear effects such as optical switching [5] and optical bistability [6,7] which is applicable in all-optical memories and all-optical signal processing devices which has become a significant interest for research recently [8][9][10]. Chalcogenide glasses offer such opportunity because of their nonlinear parameter, n2, which is about 100 to 1000 times larger compared with silica [11][12][13][14].…”