Numerical simulation of spectral transmission characteristics of single-mode-multimode-single-mode fiber structure

A calculation model of light distribution in multimode-interference based on single-mode-multimode-single-mode fiber structure was presented by using beam propagation method.A detailed simulation study of this structure in terms of the length of the multimode fiber core,the diameter of the multimode fiber core,the wavelength of the input light has been carried out.In addition,the possibility of SMS fiber structure using as fiber sensor was predicted.Furthermore,the transmission spectra of the structure for various surrounding refractive index medium were analyzed.The results show that it is consistent with the experimental findings qualitatively.