The advances in the fabrication of photonic waveguides in the past decades have led the scientific community to seek for numerical methods that could assist in the process of designing such devices. The design of photonic waveguides often requires relative errors of 10e-14 on the propagation constant to calculate the dispersion parameters. In this context, a hierarchical strategy for constructing H(curl;Ω)-conforming elements are introduced, for application in a Finite Element Method scheme for modal analysis of general electromagnetic waveguides. The hierarchical H(curl; Ω)-conforming elements are used for the transversal component of the electric field, coupled with scalar H1(Ω) elements for its longitudinal component. The Nédélec elements of the first kind were chosen, and the ease of integration with p-adaptivity schemes motivated the hierarchical construction of the Finite Element basis. The scheme is assessed by means of the analysis of well-known waveguides. The performance of higher order elements, uncommon in the Computational Electromagnetics community, is evaluated, and the importance of an accurate representation of curved geometries when using higher order elements is stressed. Modal analysis large class of waveguides, including micro-structured photonic crystal fiber, attests the accuracy of the hierarchical Finite Element basis when dealing with a design process requiring high precision on the dispersion parameters. This subject is part of a master thesis supervised by Dr. Hugo E. H. Figueroa.