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 and modes, the numerical simulation shows that the insertion loss is only less than 0.1 dB and crosstalk is less than -20 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.