الملخص

Abstract The aim of this study is to show the laser field distribution dependence on the number of missing holes in the core of the photonic crystal fiber, so that three different structure of photonic crystal fibers (PCFs) were proposed, the parameters of the proposed structures are identical; hole diameter d is 0.46 µm, pitch size Λ is 2.3 µm, while the number of the hole rings (Nr) is one for all the structures. The difference only in the number of the missing holes in the center of the core, that means PCF1 of one missing holes, PCF2 of three missing holes, and PCF3 of four missing holes. The characteristics of the PCFs structures such as effective index, dispersion, confinement losses and field distribution were calculated and discussed. The results of such study show that the increasing of the missing holes reduces the fluctuation in dispersion profile and pushing the zero dispersion wavelength (ZDW) towards the longer wavelength, in addition the confinement losses are reduced over a wide range of wavelength. This study shows, by the field distribution, that the PCFs of large core area are operated in high order mode.