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Abstract: Two designs of photonic crystal fibers with similar parameters are proposed, the difference only in the air fraction. The Air fraction of the PCF1 is 0.4, while for the second design is increased to 0.45. The propagation properties of the both designs are investigated. The results show that the zero dispersion wavelength (λZD) for PCF1 and PCF2 are pushed to the visible region far away from the 1.27µm as in traditional silica fibers. The effect of the laser pulsed power of the (Ti-Sapphire) of 0.8µm on the dispersion profile of PCF1 and PCF2 is also studied. The λZD for the PCF1 is blue shifted, while a small increment in the air fraction as in PCF2 cause red shift for λZD. On the other hand, the sensitivity of the PCF2 for the pulse power (0.3nm/kW) is 10 times more comparing with the sensitivity (0.03nm/kW) of the PCF1.

In this paper, the characteristics of photonic crystal fibers (PCFs), which have been experimentally determined in the last few years in Iran's Telecom Research Center are analyzed and compared theoretically using an effective index method. The PCFs under investigation are fabricated with a high speed drawing process that has not yet been reported elsewhere. It was shown that at higher wavelengths in PCFs; the light field is confined in the core where in shorter wavelengths the field spreads into the cladding region. This phenomenon leads to affect the numerical aperture and the normalized frequency of the PCFs, because these two parameters directly depend on the diameter of the air-hole and the spacing between them in the cladding region. The measured results show that the PCF fabricated at high drawing speeds has a loss of 12 dB/km of speed, which is a reasonable level compared to other published reports. In addition, we have shown that a lower spacing between the adjacent air-holes would reduce the loss in the PCFs. [ABSTRACT FROM AUTHOR]