High Q factor InP photonic crystal nanobeam cavities on silicon wire waveguides.
High quality (Q) factor indium phosphide (InP) based 1D photonic crystal nanobeam cavities are fabricated on silicon on insulator waveguides. Through the optimization of the fabrication process, the intrinsic Q factor of these fully encapsulated nanocavities is demonstrated to attain values higher than 100,000. Experimental and numerical investigations are carried out on the impact, on the Q factor, of the strength of the evanescent wave coupling between the cavity and the waveguide. We reveal that this coupling can result in a modification of the electromagnetic field distribution in the resonant mode, which gives rise up to a factor 4 reduction in the intrinsic Q factor for the structures under study.
Optics letters