Device with waveguide defined by dielectric in aperture of cross-track portion of electrical conductor for writing data to a recording medium

A read/write head, comprising:

• a magnetoresistive sensor;
• an electrical conductor having a cross-track portion oriented in the same direction as the magnetoresistive sensor relative to a track of a recording medium, wherein the cross-track portion includes first and second opposing surfaces, and wherein the cross-track portion defines an aperture extending from the first surface to the second surface;
• and
• a dielectric portion disposed in the aperture such that the dielectric portion defines a waveguide having a lowest-order mode cut-off frequency that is less than the frequency of energy from an energy source that propagates through the waveguide and impinges on the recording medium.

A read/write head, comprising:

• a magnetoresistive sensor;
• an electrical conductor having a cross-track portion oriented in the same direction as the magnetoresistive sensor relative to a track of a recording medium, wherein the cross-track portion includes first and second opposing surfaces, and wherein the cross-track portion defines an aperture extending from the first surface to the second surface;
• a dielectric portion disposed in the aperture such that the dielectric portion defines a ridge waveguide having a lowest-order mode cut-off frequency that is less than the frequency of energy from an energy source that propagates through the ridge waveguide and impinges on the recording medium;
• mode selection means for selecting a mode of transmission of the energy from the energy source;
• and
• means for focusing energy from the energy source onto the dielectric portion.

A read/write head, comprising:

• a magnetoresistive sensor;
• an optical waveguide;
• an electrical conductor having a cross-track portion oriented in the same direction as the magnetoresistive sensor relative to a track of a recording medium, wherein the cross-track portion includes first and second opposing surfaces, and wherein the cross-track portion defines an aperture extending from the first surface to the second surface;
• a dielectric portion disposed in the aperture such that the dielectric portion defines a waveguide having a lowest-order mode cut-off frequency that is less than the frequency of energy received by the optical waveguide;
• and
• means for focusing the energy received by the optical waveguide onto the dielectric portion at the first surface of the cross-track portion of the electrical conductor.