Method of making light converting systems using thin light trapping structures and photoabsorptive films

A method of making a light converting optical system, comprising:

• providing a layered light trapping structure, wherein the layered light trapping structure comprises
• a first optical layer;
• a plurality of linear grooves formed in a front surface of the first optical layer and each having a triangular cross-section, wherein at least some of the plurality of linear groves are arranged into a regular array of alternating ridges and valleys extending parallel to one another along a straight line and between two different edges of the first optical layer, wherein each of the plurality of linear grooves is configured to reflect first light rays having first incidence angles with respect to a surface normal using a total internal reflection and deflect second light rays having second incidence angles with respect to the surface normal using refraction;
• a diffuse reflector approximately coextensive with and positioned parallel to the first optical layer, wherein the diffuse reflector is formed from a thin sheet of a diffuse reflective material;
• an optical film approximately coextensive with and positioned parallel to the first optical layer between the front surface and the diffuse reflector, wherein the optical film comprises an active layer configured to partially transmit and partially absorb light in a visible spectrum propagating through the optical film in a transverse direction, wherein active layer comprises a first light converting semiconductor material having a first bandgap and a second light converting semiconductor material having a second bandgap which is different than the first bandgap, wherein a thickness of the active layer is less than a minimum thickness sufficient for absorbing substantially all light in the visible spectrum traversing through the active layer in a single pass;
• providing a light source configured to emit light in the visible spectrum;
• and
• positioning the layered light trapping structure in energy receiving relationship with respect to the light source.

A method of making a light converting optical system, comprising:

• providing a layered light trapping structure, wherein the layered light trapping structure comprises
• a first optical layer;
• a plurality of linear grooves formed in a front surface of the first optical layer and each having a triangular cross-section, wherein at least some of the plurality of linear groves are arranged into a regular array of alternating ridges and valleys extending parallel to one another along a straight line and between two different edges of the first optical layer, wherein each of the plurality of linear grooves is configured to reflect first light rays having first incidence angles with respect to a surface normal using a total internal reflection and deflect second light rays having second incidence angles with respect to the surface normal using refraction;
• a diffuse reflector approximately coextensive with and positioned parallel to the first optical layer, wherein the diffuse reflector is formed from a thin sheet of a diffuse reflective material;
• an optical film approximately coextensive with and positioned parallel to the first optical layer between the front surface and the diffuse reflector, wherein the optical film comprises an active layer configured to partially transmit and partially absorb light in a visible spectrum propagating through the optical film in a transverse direction, wherein a thickness of the active layer is less than a minimum thickness sufficient for absorbing substantially all light in the visible spectrum traversing through the active layer in a single pass;
• providing a light source configured to emit light in the visible spectrum;
• and
• positioning the layered light trapping structure in energy receiving relationship with respect to the light source.