Demonstration of Dual-Mode Photonic Integrated Circuit Based on Inverse-Designed Photonic Components

We design and experimentally demonstrate an ultra-compact dual-mode mode-division multiplexing (MDM) photonic integrated circuit (PIC), which supports on-chip optical signal mode-order-based routing and mode-independent broadcasting. The MDM circuit is composed of inverse-designed three multiplexers, one 3-dB power splitter, three bends and one crossing based on photonic-crystal-like subwavelength structure. The measured excess loss and crosstalk of the fabricated MDM circuit are lower than 5.9 dB and −13 dB over a 60 nm observable wavelength span, respectively. The experiment results of single-channel 25 Gbit/s optical signal transmission show that only 1.2-dB power penalty is introduced through the MDM circuit at a bit-error-rate of 10
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.