Mohammadreza Esfandiarifar - Department of Electrical Engineering, Kermanshah Science and Research Branch, Islamic Azad University, Kermanshah, Iran.- Department of Electrical Engineering, Kermanshah Branch, Islamic Azad University, Kermanshah, Iran.
Mazdak RadMalekshahi - Department of Electrical Engineering, Razi University, Kermanshah, Iran.

In this paper, the bistability characteristics of chalcogenide nonlinear FBGs are studied and investigated. The effect of length and third order nonlinearity on On-Off switching ratio and intensity distribution in FBG are investigated numerically. We obtained that there exist an optimum FBG length, that on-off switching ratio is maximized and is independent of the third order nonlinearity. The equations of bistability in FBG is presented and an analytical equation is proposed and extracted for bistability behavior in FBG

Fiber, Grating, Bistability, Switch