Engineering defect modes in symmetry reduced 1D photonic crystal nanobeam waveguide

In this paper, nanobeam cavity studies were performed on low-symmetric 1D photonic crystals. An eligible comparison between low-symmetric structure and a regular cavity is held. Due to nature of the resonance, reduced symmetry is expected to decrease confined resonance field; however, authors focused on the tuning of the extra parameters arisen from degenerated symmetry and promising results are obtained. Quality factor enhancement with respect to varying structural parameters is observed. To the best of authors' knowledge, this is the first time that the cavity is enhanced with controlled low symmetric structures. Also, mode profile variation and spectral response shift due to structural parameters are analyzed. Results hold potential for further integrated photonic device research such as filtering, optical memory units, quantum cryptology.