Reconfigurable Reflective Arrayed Waveguide Grating (R-Rawg)

A reconfigurable reflective arrayed waveguide grating (R-RAWG) has been designed, fabricated and tested in a silicon nitride platform. The R-RAWG has a number of advantages if compared to a traditional arrayed waveguide grating (AWG) as smaller footprint and the capability to correct to phase errors induced by fabrication defects. To implement this design, we have used tunable reflective michelson loops that produce a broadband response without the need of a modified or additional fabrication process. This approach opens the possibility to implement this design in almost any fabrication platform. By controlling the amplitude and phase of each arm, more than 12 different spectral shapes have been obtained with more than 20 dB of extinction ratio. The control is based on a new method using optimization algorithms borrowed from machine leaning developed using only the power spectrum response of one output to adapt all the variables. The reconfiguration of the band shape, the possibility to adapt the filter to the desired spectrum in one or multiple bands and the fabrication-friendly implementation for mass production make this device suitable for multiple applications as LIDAR, spectroscopy, OCT, Microwaves, Telecommunications among others.