Effect of separation length on dual fibre Bragg gratings

This paper will investigate the transmission series of dual FBGs when the separation length between two FBGs is varied from 0.5 cm to 5.5 cm. The transfer matrix 2×2 is applied to complete the work. The introduction of separation length affects the transmission spectrum, indicated by the numbers of minimum dip values. Result shows that increasing the separation length between two FBG's lead to the formation of phase shift and increases the number of minimum transmission dip. © 2010 SPIE.