Monolithically Integrated Three-Dimensional Chiral Metamaterials

Metamaterials, which consist of artificial meta-atoms with subwavelength feature size, offer strong capability for manipulating the multiple degrees of freedom of electromagnetic waves. However, their practical applications are usually constrained by the limitations of specific manufacturing processes, including the optical responses of materials, interface compatibility, lithography resolution, and so on. Here, we propose a monolithic integration manufacturing approach of 3D metamaterials by using low-temperature co-fired ceramic (LTCC) technology. In the concept proof experiment, we design and fabricate the 3D chiral metamaterials that exhibit strong circular dichroism in the millimeter wave regime. It is achieved by embedding spatially variant silver meta-atoms into a low-loss LTCC matrix through screen-printing and low-temperature co-firing processes. This monolithic integration strategy opens new avenues for making 3D metamaterials working in the millimeter wave and even THz spectral region, and may have great potentials in developing ultra-compact electromagnetic systems for sensing, communications, computing, and imaging applications.