A sensor device comprising: a plurality of sensor elements ; and a plurality of optical filters disposed over the the plurality of sensor elements , wherein each of the optical filters includes: a plurality of dielectric layers ; and a plurality of silver or silver alloy metal layers stacked in alternation with the plurality of dielectric layers , wherein each of the plurality of metal layers is substantially uniform in thickness throughout a central portion of the optical filter , and tapers off in thickness at a periphery of the optical filter to has a tapered edge , at the periphery of the optical filter (200,), that is protectively covered by one or more of the plurality of dielectric layers , and each of the plurality of metal layers is separated from a substrate of an optical filter , of the one or more optical filters, using at least one the plurality of dielectric layers , and each of the plurality of metal layers is encapsulated by two nearest of the plurality of dielectric layers ; and wherein each of the one or more optical filters further includes a plurality of corrosion-suppressing layers disposed between the plurality of dielectric layers and the plurality of metal layers , and the metal layers are encapsulated by the corrosion-suppressing layers, characterised in that the plurality of sensor elements are disposed in a two-dimensional array, and the plurality of optical filters are disposed in a corresponding two-dimensional array, and the plurality of optical filters includes different types of optical filters having different passbands from one another. a plurality of sensor elements ; and a plurality of optical filters disposed over the the plurality of sensor elements , wherein each of the optical filters includes: a plurality of dielectric layers ; and a plurality of silver or silver alloy metal layers stacked in alternation with the plurality of dielectric layers , wherein each of the plurality of metal layers is substantially uniform in thickness throughout a central portion of the optical filter , and tapers off in thickness at a periphery of the optical filter to has a tapered edge , at the periphery of the optical filter (200,), that is protectively covered by one or more of the plurality of dielectric layers , and each of the plurality of metal layers is separated from a substrate of an optical filter , of the one or more optical filters, using at least one the plurality of dielectric layers , and each of the plurality of metal layers is encapsulated by two nearest of the plurality of dielectric layers ; and a plurality of dielectric layers ; and a plurality of silver or silver alloy metal layers stacked in alternation with the plurality of dielectric layers , wherein each of the plurality of metal layers is substantially uniform in thickness throughout a central portion of the optical filter , and tapers off in thickness at a periphery of the optical filter to has a tapered edge , at the periphery of the optical filter (200,), that is protectively covered by one or more of the plurality of dielectric layers , and each of the plurality of metal layers is separated from a substrate of an optical filter , of the one or more optical filters, using at least one the plurality of dielectric layers , and each of the plurality of metal layers is encapsulated by two nearest of the plurality of dielectric layers ; and <EOS>