Optical waveguide unit, array, and flat lens

An optical waveguide array, comprising:

• a plurality of optical waveguide units, each optical waveguide unit comprising:
• a plurality of reflecting units being the same in structure, each reflecting unit being any one or a combination of any two of:
• a metal layer, a total reflecting layer, and a medium reflecting layer;
• and
• a plurality of sub waveguides stacked on each other, each of two sides of each sub waveguide being provided with one reflecting unit, at least two of the plurality of sub waveguides having different heights in a stacking direction of the plurality of sub waveguides, and the different heights of the sub waveguides being corresponding to different incident angle directions,
• each optical waveguide unit having a rectangular cross section, and the plurality of optical waveguide units being joined in parallel;
• an outer contour of the optical waveguide array is rectangular, and an extending direction of the optical waveguide unit and at least two sides of the outer contour of the optical waveguide array form an angle of 30 to 60 degrees.

A flat lens, comprising:

• two transparent substrates, each transparent substrate having two optical surfaces;
• and
• two optical waveguide arrays, each optical waveguide array comprising a plurality of optical waveguide units, each optical waveguide unit comprising:
• a plurality of reflecting units being the same in structure, each reflecting unit being any one or a combination of any two of:
• a metal layer, a total reflecting layer, and a medium reflecting layer;
• and
• a plurality of sub waveguides stacked on each other, each of two sides of each sub waveguide being provided with one reflecting unit, at least two of the plurality of sub waveguides having different heights in a stacking direction of the plurality of sub waveguides, and the different heights of the sub waveguides being corresponding to different incident angle directions,
• each optical waveguide unit having a rectangular cross section, and the plurality of optical waveguide units being joined in parallel;
• an outer contour of the optical waveguide array is rectangular, and an extending direction of the optical waveguide unit and at least two sides of the outer contour of the optical waveguide array form an angle of 30 to 60 degrees;
• the two optical waveguide arrays being arranged between the two transparent substrates by means of glue, and optical waveguide extending directions of the two optical waveguide arrays being arranged orthogonally.