Typical Reflection Spectra (b) unwanted reflections (a typical reflection spectrum of a 1 cm long FBG with relatively low RI contrast. The height of the peak is 100% reflection and the width of the reflection band is. 2 nm;(b) same grating with a stronger contrast. The reflection band has been broadened; (c) same grating as part (a)but after apodisation. Note the reflection peak is now not quite 100%Typical Reflection Spectra (a) typical reflection spectrum of a 1 cm long FBG with relatively low RI contrast. The height of the peak is 100% reflection and the width of the reflection band is .2 nm; (b) same grating with a stronger contrast. The reflection band has been broadened; (c) same grating as part (a) but after apodisation. Note the reflection peak is now not quite 100%