1  ×  5 polarization-independent photonic crystal power splitters designed by the particle swarm optimization algorithm

We propose a 1×5 polarization-independent power splitter based on a photonic crystal. Control air holes at the waveguide junctions are introduced to realize equal and unequal distribution of beams with high transmittance. In order to improve optimization efficiency and splitting performance, according to the target splitting ratios, the particle swarm optimization algorithm is used to reverse-design the radii and offsets of control air holes. The results show that, for both TE and TM polarizations, the additional losses are less than 1.2 dB, the power splitting uniformity for equal-ratio splitters is below 1.1 dB, and the mean square errors for non-equal splitters are below 2×10−4 in 1545–1555 nm. Additionally, the response times of power splitters with different ratios are less than 1.1 ps. The designed photonic crystal power splitters have designable power splitting ratio, small size, and can achieve polarization-independent transmission over a certain range, which will have good application prospects in the future all-optical communication network, photon high-density integration, and other fields.