Inverse Design of Terahertz Optical Power Splitters Using the Particle Swarm Optimization Method

This letter proposes 50:50 TE terahertz power splitters based on digitized metamaterials. The components are optimized using the parti-cle swarm optimization algorithm. The digitized metamaterials are formed as a silicon slab with circular air holes atop a silicon dioxide substrate. The insertion losses of optimized structures containing air holes with a radius of 9 mu m and air holes with different radii (9 mu m and 7 mu m) are less than 3.9 dB and 3.65 dB, respectively, over a frequency range of 0.87-1.09 THz. The footprint of the proposed devices is 400 mu m x 350 mu m. The devices have excellent characteristics, such as compactness, efficiency, all-dielectric properties, and compatibil-ity with CMOS fabrication technologies, and can become vital components of most terahertz-wave routing circuits.