Light source including effective refractive index controlling pattern

A light source comprising:

• a substrate;
• a light emitting layer provided on the substrate and configured to emit light;
• a plurality of unit structures provided on the light emitting layer;
• a barrier layer covering the unit structures;
• and
• a planarization layer covering the unit structures and the barrier layer,
• wherein the unit structures are arranged along a radial direction and a tangential direction to form an effective refractive index controlling pattern,
• wherein the effective refractive index controlling pattern is configured to control the effective refractive index through a first variable defined by a width of each of the unit structures, a second variable defined as a period in which the unit structures are arranged in the tangential direction, a third variable defined as a period in which the unit structures adjacent in the radial direction are arranged, and a fourth variable defined as a difference between a refractive index of the unit structures and a refractive index of a material surrounding the unit structures,
• wherein the first variable is smaller than a central wavelength of the light emitted from the light emitting layer,
• wherein the effective refractive index controlling pattern has rotational symmetry.

A light source comprising:

• a substrate;
• a light emitting layer provided on the substrate and configured to emit light;
• and
• a plurality of lenses provided on the light emitting layer,
• wherein the lenses are disposed repeatedly and are arranged to fill a plane,
• wherein the lenses each have an effective refractive index controlling pattern including a plurality of unit structures arranged along a radial direction and a tangential direction,
• wherein the effective refractive index controlling pattern is configured to control the effective refractive index through a first variable defined by a width of each of the unit structures, a second variable defined as a period in which the unit structures are arranged in the tangential direction, a third variable defined as a period in which the unit structures adjacent in the radial direction are arranged, and a fourth variable defined as a difference between a refractive index of the unit structures and a refractive index of a material surrounding the unit structures,
• wherein the first variable is smaller than a central wavelength of the light emitted from the light emitting layer,
• wherein the effective refractive index controlling pattern has rotational symmetry.