Influence of intra-cavity loss on transmission characteristics of fiber Bragg grating Fabry–Perot cavity

Abstract

A theoretical model of the fiber Bragg grating Fabry-Perot (FBG-FP) transmission spectrum considering loss of FBG and intra-cavity fiber is presented. Several types of FBG-FPs are inscribed experimentally, and their spectra are measured. The results confirm that weak intra-cavity loss is enhanced at the resonance transmission peak, that is, loss of transmission peaks is observably larger than other wavelengths. For FBG-FPs with multi resonance peaks, when the resonance peak wavelength is closer to the Bragg wavelength, the more significant loss effect of resonance transmission peak is exhibited. The measured spectra are fitted with the presented theoretical model. The fitted coefficient of determinations are near 1, which proves the validity of the theoretical model. This study can be applied to measure FBG loss more accurately, without a reference light. It can play an important role in FBG and FBG-FP writing process optimization and application parameter optimization.

Hybrid Fiber Optic Sensor, Based on the Fabry–Perot Interference, Assisted with Fluorescent Material for the Simultaneous Measurement of Temperature and Pressure

“…Much effort has been put into compensating the influence of temperature during pressure measurement [ 16 , 17 ]. Some novel fiber-optic F–P sensors with hybrid configurations have been designed and manufactured, such as one sensor integrating two cascaded F–P cavities [ 18 , 19 , 20 ], two fiber Bragg gratings (FBG) with different sensitivity coefficients [ 21 , 22 ], and attaching FBG to an extrinsic F–P interferometer [ 23 , 24 , 25 ]. These approaches have improved the accuracy of pressure measurement, however they are very complex in configuration and difficult to manufacture.…”