Metal mask fabrication with an inkjet printer for AWG phase trimming using a photosensitive refractive index change

We report a simple method for fabricating a metal mask with wet etching designed to reduce the adjacent crosstalk of arrayed-waveguide gratings (AWGs) by using a photoinduced refractive index change. This process utilizes a commercially available inkjet printer and a copy machine, and so the resolution of the fabricated window pattern is not very high. However, the fabricated mask enables us to achieve a great reduction in adjacent crosstalk because it depends solely on a slowly varying component in the phase error distribution of an AWG.