Optical isolator with optical polarizers having high transmission, corrosion resistance and reduced thickness

An optical isolator comprising;

• a polarizer, having a first polarization axis, for directly receiving an optical signal from an optical signal source and for outputting at least a part of the optical signal;
• a Faraday rotator for directly receiving and for rotating a polarization of the at least part of the optical signal output by the polarizer, and for outputting at least a part thereof as a rotator output optical signal;
• and
• an analyzer, having a second polarization axis, for directly receiving the rotator output optical signal and for outputting at least a part thereof, wherein:
• the polarizer and the analyzer are coupled to first and second opposed surfaces of the Faraday rotator;
• and
• each of the polarizer and the analyzer comprise:
• a multi-layer dielectric substrate;
• a plurality of elongated dielectric ridges positioned or disposed in spaced relation to each other in contact with a surface of the multi-layer dielectric substrate, wherein each dielectric ridge has a length direction that extends along the surface of the multi-layer dielectric substrate and each dielectric ridge includes a pair of spaced sides that extend away from the surface of the multi-layer dielectric substrate and a top extending between the spaced sides opposite the surface of the multi-layer dielectric substrate;
• an electrically conductive coating on each side of each dielectric ridge;
• a groove or trench between the electrically conductive coatings on facing sides of adjacent or proximate pairs of dielectric ridges;
• and
• a solid dielectric in each groove or trench between the facing sides of the adjacent or proximate pairs of dielectric ridges, wherein said solid dielectric also covers the tops of the plurality of dielectric ridges, wherein:
• the plurality of dielectric ridges of the polarizer are coupled to the first surface of the Faraday rotator via the multi-layer dielectric substrate of the polarizer with the solid dielectric that also covers the tops of the plurality of dielectric ridges of the polarizer disposed on a side of the polarizer opposite the multi-layer dielectric substrate of the polarizer;
• and
• the plurality of dielectric ridges of the analyzer are coupled to the second surface of the Faraday rotator via the multi-layer dielectric substrate of the analyzer with the solid dielectric that also covers the tops of the plurality of dielectric ridges of the analyzer disposed on a side of the analyzer opposite the multi-laver dielectric substrate of the polarizer.