Parallel arrayed waveguide grating for wavelength-mode hybrid multiplexing.

The combination of wavelength division multiplexing (WDM) and mode division multiplexing (MDM) will increase the optical communication capacity significantly. In this configuration, we need multiple WDM devices serving as the inputs of the MDM device to excite modes at all the wavelengths. However, there is still no demonstration of integrated parallel WDM devices specifically designed for wavelength-mode hybrid multiplexing. Here, we propose and demonstrate a single 2 × 8 arrayed waveguide grating (AWG) for the multiplexing of 2 linearly polarized (LP) modes at 4 wavelengths with an MDM device. This parallel AWG concept can be further extended to support more wavelengths and introduce more spatial modes for high-capacity data transmission.