Low-loss and compact, dual-mode, 3-dB power splitter combining a directional coupler, a multimode interferometer, and a Y-junction

Multimode power splitters are the fundamental building blocks in mode division multiplexing systems. In this paper, we propose a low-loss and compact, dual-mode, 3-dB power splitter for the two lowest TE modes combining three different structures, including a directional coupler, a multimode interferometer, and a Y-junction. The coupling length of the proposed device is only 7.2 µm. For both TE 0 and TE 1 modes, the numerical simulation shows that the insertion loss is only less than 0.1 dB and crosstalk is less than −20dB at the wavelength range of 1520–1580 nm. The working bandwidth can cover the entire C-band. It offers a potential solution for a 3-dB power splitter of the two lowest TE modes.