Effect of thickness deviation on the absorption of graphene in photonic crystal microcavity

The effect of thickness deviation on the optical properties of graphene-based optical microstructure was studied by using the transfer matrix method. Machining errors led to inconsistencies in the thicknesses of different parts and resulted in an offset of absorption peak, thus significantly reducing the average light absorption. The 3-nm deviation decreased the light absorption of graphene-optical microstructure by approximately 3.5 times. However, if the machining error is included in the design, then a relatively small Q value will help reduce the effect of machining error and the light absorption can be enhanced by about 32%.