Photonic Crystal Fiber in Photonic Crystal Fiber for Residual Dispersion Compensation Over ${\rm E} + {\rm S} + {\rm C} + {\rm L} + {\rm U}$ Wavelength Bands

A photonic crystal fiber in photonic crystal fiber (PCF-in-PCF) architecture is numerically investigated for residual dispersion compensation in optical transmission link. The optimized structure shows a flattened and high average dispersion of -457.4 ps/nm/km in the wavelength range of 1360 nm to 1690 nm. The sensitivity of the fiber dispersion properties to a ±2% variation in the optimum parameters is studied for practical conditions. Additionally, the effect of variation in the structure parameters on effective mode area is simulated to understand its relationship to light confinement.