Design of highly nonlinear dispersion-flattened square photonic crystal fiber for medical applications

In this paper, we report the design of a highly nonlinear dispersion flattened high-index-core square photonic crystal fiber (PCF) for applications in optical coherence tomography (OCT). The finite-difference method with an anisotropic perfectly matched boundary layer is used as a numerical simulation tool. A set of optimized design parameters numerically resulted in a nonlinear coefficient of 79.9W−1 km−1 and a dispersion of −0:186 ps/(nm·km) at a wavelength of approximately 1.06 μm. Owing to its high nonlinear coefficient and flattened dispersion, the PCF is expected to be suitable for broadband supercontinuum generation, which is considered very important in OCT medical applications.