Linearly chirped and weakly tilted fiber Bragg grating edge filters for in-fiber sensor interrogation

Power-referenced in-fiber edge filters based on a linearly chirped and weakly tilted fiber Bragg gratings (TFBG) are proposed and experimentally demonstrated. A strongly chirped TFBG with a polymer coating provides a smooth transfer function with up to 0.7 dB/nm of discrimination over the C-band. The slope profile of UV-induced chirped TFBG can be easily tailored by adjusting the tilt angle using only one chirped phase mask. Interrogators based on chirped TFBG can provide temperature-self-compensated, broadband, robust and cost-effective in-fiber demodulation for FBG sensing applications.