Research on dual-transmission cross-shaped microcavity metamaterials in the mid-infrared region

Abstract

Abstract Mid-infrared detection technology is widely used in military and civilian applications with its unique advantages. The filter is the core component of the mid-infrared detection system, realizing controllable modulation of its dual-band transmission peak is an important prerequisite for optimizing detector performance. In this paper, a cross-shaped microcavity structure metamaterial based on gold material is designed to achieve mid-infrared dual-band transmission. By changing the width of the microcavity and the width of the gap, the controllable modulation of the dual-band transmission peaks is achieved, corresponding to the dual-band ranges of 3.23 ~ 3.46 µm and 4.06 ~ 4.60 µm. The maximum transmission of the resonant transmission peaks λI and λII can reach 94.5% and 92.6%, respectively. The corresponding FOM is up to 17.70. This study provides a theoretical basis for the preparation of dual-band transmission filters in the mid-infrared band.