Figure 1
From: A new gas detection technique through cross-correlation with a complex aperiodic FBG
(a) Custom design of the aperiodic FBG as represented by amplitude (\(\kappa\)) and phase (\(\theta\)) along the axis of the fibre. (b) Schematic representation of the index modulation and phase variation in the core of a complex aperiodic FBG optical fiber. (c) Comparison of the complex FBG transmission response (red) with the p-band absorption features of \(C_2H_2\) (black) which it was designed to mimic. (d) Reflection spectrum of the complex FBG filter.
