Asymmetric transmission and reflection spectra of FBG in single-multi-single mode fiber structure.

Optics express

PubMedID: 25969258

Chai Q, Liu Y, Zhang J, Yang J, Chen Y, Yuan L, Peng GD. Asymmetric transmission and reflection spectra of FBG in single-multi-single mode fiber structure. Opt Express. 2015;23(9):11665-73.
We give a comprehensive theoretical analysis and simulation of a FBG in single-multi-single mode fiber structure (FBG-in-SMS), based on the coupled mode analysis and the mode interference analysis. This enables us to explain the experimental observations, its asymmetric transmission and reflection spectra with the similar temperature responses near the spectral range of Bragg wavelengths. The transmission spectrum shift during FBG written-in process is observed and discussed. The analysis results are useful in the design of the SMS structure based sensors and filters.