Display with a waveguide coated with a meta-material

A method for displaying display light using an optical waveguide display that includes an optical waveguide having a first surface and a second surface, the second surface opposing the first surface, the optical waveguide including a first diffractive part and a second diffractive part optically coupled to the first diffractive part, the method comprising:

• receiving display light at said first diffractive part on the first surface of the optical waveguide and via the second surface of the optical waveguide, and therewith diffracting the received display light for guided propagation along the optical waveguide by total internal reflection (TIR) to the second diffractive part;
• and
• at the second diffractive part on the first surface or the second surface of the optical waveguide, receiving and diffracting light from the first diffractive part to an angle for output from the optical waveguide via the first surface or the second surface of the optical waveguide;
• wherein at least a portion of the first surface of the optical waveguide and/or the second surface of the optical waveguide is coated with a material having a refractive index of value substantially equal to or less than 1.0.

An apparatus for producing an optical display comprising:

• an optical waveguide having a first surface and a second surface, the second surface opposing the first surface, the optical waveguide including
• a first diffractive part on the first surface of the optical waveguide, the first diffractive part arranged to receive display light via the second surface of the optical waveguide and to diffract the display light into an angle for guided propagation along the optical waveguide, and
• a second diffractive part on the first surface of the optical waveguide, the second diffractive part optically coupled to the first diffractive part and arranged to receive and to diffract light from the first diffractive part to an angle for output from the optical waveguide via the second surface of the optical waveguide;
• wherein at least a portion of the first surface of the optical waveguide and/or the second surface of the optical waveguide are coated with a material having a refractive index of value substantially equal to or less than 1.0, the material comprising a meta-material.