As a kind of special wave guide, photonic crystal fibers have their unique configuration and characteristic. Since being invented , PCFs have got much attention and become a hot research point in the fields of optics and electronics. This paper starts from the development of PCFs, outline their construction and constituents, introduce the odd characteristic of PCFs , the actuality of their study and the way of application for photo-electronic communication.
Based on normal step-index fiber model, this paper investigated FCFs and calculated the effective-index and dispersion constant of PCFs by using vector effective index method. It is important to input some-kind of material into the cladding of PCFs, whose index could be controlled. And we also studied the relationship between the index of stuffing and the effective index of the cladding of PCFs, the effective index of PCFs and the dispersion property too. The characteristic equations of PCFs were got, then we found the relationships among the effective index, the dispersion character of PCFs and the index of stuffing. Comparing with general PCFs, the distinction of the dispersion property of the new PCFs and general PCFs is analysed.