A novel design of photonic crystal fiber containing square holes in a square lattice with high dispersion tolerance, flattened dispersion and low effective mode area

A unique photonic crystal fiber (PCF) which consists of circular core surrounded by square lattice cladding is presented. The square lattice cladding further consists of square-shaped air holes. Flattened chromatic dispersion (D) is obtained for this structure in the C and L communication bands at different values of the ratio of square hole width to the pitch (d/Lambda) of the PCF. The main advantage of this structure is its high dispersion tolerance capability for change in the distance between core and square holes cladding (d(1)). There is observed only about 2.4 ps/nm-km variation in D for -5 to +5% change in d(1). Effective mode area has been obtained for this PCF structure which comes out to be small enough to make this fiber suitable to be used in non-linearity related applications.