In this paper, a new simple structure of index-guiding photonic crystal fiber (PCF) is designed and presented. In this PCF, dispersion, confinement loss, and effective mode area characteristics are investigated in the second communication window (1.55？μm). Since 1.55？μm wavelength is widely used in optical communication systems, we try to optimize the PCF characteristics in this wavelength by designing an index-guiding PCF and three versions of optimized PCF. The results show that the dispersion is obtained very close to zero around 4.6×10？4 ps/(nm·km). Also, the confinement loss is 2.303×10？6 dB/km and effective mode area is as small as 2.6？μm2.
