Broadband and compact silicon photonic power splitter with enhanced coupling of subwavelength waveguides

Power splitters are crucial components in optical communication, sensing, and computing, but their size and operational bandwidth remain constrained. An anti-symmetric tapered sub-wavelength grating waveguide (ATSWG)-based power splitter is theoretically and experimentally verified with a bandwidth of 120 nm and a coupling length of 6 μm. For 3-dB power splitters, the insertion loss is less than 0.94 dB. By varying the spacing ratio of the coupled waveguides, the power splitters are able to achieve different designs with spectral ratios such as 90:10, 80:20, 75:25, and 50:50. This remarkable process resilience positions the ATSWG splitter as a promising candidate for high-yield integration.