Research On Photonic Crystal Fibers And Coupling

In recent years, remarkable properties of optical fibers with a detect core region and a periodicity surrounding silica/air photonic crystal (PC) cladding have been reported. It is a kind of two dimensional photonic. Different from total internal reflection (TIR) of traditional fiber, photonics crystal fiber (PCF) guides wave through photonic band gap (PBG) effect. Light can't propagate in PCF if its frequency failed into the band gap. So PCF represents lots of much remarkable properties than traditional fiber in the fiber losses, dispersion, nonlinear and transmission with single-mode. Now, researches on PCF have revealed that PCF would be applied in a very wide range.At first, we analyzed the mode-guide of PCF with effective-index model. And it is proved with finite-element mathematical model. We found the disciplinarian of the variation of the mode-guide of PCF with its structure parameters.Secondly, with these models mentioned above, effect on the coupling losses by the change of the structure of PCF is discussed. We found how the structure parameters of PCF influenced the losses of the mode spot size offsets which were the main losses while PCF splices to SMF. Fresnel reflection on the interface between two fibers which is the second important losses had also been discussed.At last, we analyzed the coupling properties of endless single mode PCF with SMF and flat dispersion PCF with SMF as an example.