In this paper, design of the RII triple-clad structure as a dispersion flattened optical fiber including small pulse broadening factor as well as small dispersion and its slope applicable in broadband and fast communication is considered. The proposed optimization technique is based on the Genetic Algorithms (GA) consisting suitable fitness function for each application. The putting forward design method introduces the pulse broadening factor (?/?0) about 1.0016 after 200 Km propagation at the zero dispersion wavelength that is so excellent compared to the structure (1.2794) reported in  recently. Meanwhile, the proposed structure provides high bit rate (more than 197.8 Gb/Sec at 100 km), large dispersion length (larger than 17400 km), uniform dispersion slope ([0.04,-0.08] ps/km/nm2) and broad bandwidths as well as small and uniform dispersion (smaller than 2.02 ps/km/nm) at [1.55-1.7] μm wavelength interval even for core diameter larger than 4.62 μm. Another important thing discussed in this paper is a proposal for optimization of the broadening factor on large wavelength duration, which is necessary for large bandwidth applications. The suggested technique is capable to minimize the pulse broadening factor over duration of wavelengths that is necessary for large bandwidth applications such as dense wavelength division multiplexing (DWDM) and optical time division multiplexing (OTDM). Our calculation for extracting optical properties of the proposed structure is evaluated analytically. For this purpose modal analysis of these fibers for obtaining possible wave vectors for given system parameters are done using Transfer Matrix Method (TMM) in cylindrical coordinate.
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