Shortcut to adiabaticity in a silicon polarization splitter rotator using multi-wavelength adiabaticity engineering

We introduce adiabaticity engineering in coupled waveguide devices to achieve shortcuts to adiabaticity in multi-wavelength systems. By engineering the adiabaticity distribution using a single control parameter, we obtain large operating bandwidth in a compact device. Multi-wavelength adiabaticity engineering is applied to the design of silicon polarization splitter-rotators. The total length of the designed polarization splitter-rotator is 141 μm, and simulations show that the device exhibits extinction ratios above 28 dB and 16 dB for the TE₀ and TM₀ modes, respectively, with a bandwidth of 300 nm (from 1.4 μm to 1.7 μm). The fabrication tolerance of the designed device is also simulated.