IMPROVED THERMAL MANAGEMENT IN LASER-BASED LIGHTING USING A TRUNCATED BALL LENS

The invention provides a system (1000) comprising (i) a light emitting layer (100), (ii) a first lens (200), and a thermal conductor (300), wherein: -the light emitting layer (100) comprises luminescent material (150), wherein the luminescent material (150) is configured to generate luminescent material light (151) upon excitation with light source light (11) from a first light source (10) comprising a wavelength where the luminescent material (150) can be excited, wherein the light emitting layer (100) comprises a light receiving area (110) having a light receiving area size A1; -the first lens (200) comprises a truncated ball shaped lens (250) having a curved lens surface (215) having a radius R0 relative to a central point (O), and a planar lens surface (225) configured at a first distance d1 from the central point (O), wherein the planar lens surface (225) has a planar lens surface area size A2, wherein the first lens (200) comprises a lens material (205) having an index of refraction n at a predetermined wavelength λ1 selected from a wavelength in the UV, visible, and infrared, wherein d1=x*R0/n, wherein 0.9≤x≤1.1, wherein the planar lens surface area size A2 is larger than the light receiving area size A1, wherein the first lens (200) is configured to concentrate light received at the curved lens surface (215) to provide light emanating from the planar lens surface (225), wherein the planar lens surface (225) is directed to the light receiving area (110); and -the thermal conductor (300) is configured in thermal contact with one or more of the light emitting layer (100) and the first lens (200).