摘要
Optical power splitters(OPSs) are essential components in the photonic integrated circuits. Considerable power splitting schemes have been reported on the silicon-on-insulator platform. However, the corresponding device lengths are enlarged, and polarization-sensitive operations are usually encountered when the splitting channels are increased from two to five. In this paper, a novel power splitting model is proposed to overcome these limitations.Here, fan-out bending subwavelength grating(FBSWG) metamaterials instead of classical straight SWGs are leveraged to expand the input TE/TM mode in an ultracompact region and further bend its wavefronts. By using N-angled tapers to match bending wavefronts, the light expanded by FBSWGs can be collected and evenly distributed into N output channels. Based on such a model, three OPSs are designed and experimentally demonstrated, which are the shortest polarization-independent 1 × 3, 1 × 4, and 1 × 5 OPSs reported until now to our knowledge. The characterizations show low insertion losses(<1.2 dB, <1.35 dB, and <1.65 dB) and uniformities(<0.9 dB, <1 d B, and <1 d B) over bandwidths of 54 nm, 49 nm, and 38 nm for the 1 × 3, 1 × 4, and 1 × 5OPSs, respectively. For the first time, an ultracompact device length of <4.3 μm and a polarization-independent operation can be maintained simultaneously as the output splitting channels are increased.
基金
Scientific Research Foundation of the Graduate School of Southeast University(YBPY2135)
Natural Science Foundation of Jiangsu Province(BK20211163)
National Natural Science Foundation of China(11574046,12004092)。