Inverse Design of Compact Silicon Dual-mode Demultiplexer and Power Splitter

We report the inverse design and demonstration of silicon dual-mode demultiplexer and power splitter with footprints of
$3.88\times 2.35\mu \mathrm{m}^{2}$
and
$5.4\times 5.4\mu \mathrm{m}^{2}$
, respectively. The demultiplexer shows a measured insertion loss of 0.5 dB and an inter-mode crosstalk of −13.2 dB at 1550 nm. The dual-mode power splitter has an excess loss of 1.1 dB and an inter-mode crosstalk of −22.4 dB at 1550 nm.