Patent ID: 7655475

Claim:
A sensor substrate ( 702 , 900 ) formed from a material of a first refractive index, adapted to receive incident light emitted from a luminescence material of a second refractive index optically coupled thereto, for use in an environment having a third refractive index, the third refractive index being less than the second refractive index and the second refractive index being less than the first refractive index, the sensor substrate comprising: an upper surface ( 701 , 710 ) having a plurality of integral solid frustoconical protuberances ( 707 , 710 ) protruding therefrom, each of the protuberances having only outer side walls extending upwardly from the upper surface of the sensor substrate and terminating in a protuberance upper surface, the protuberance upper surface being offset from the outer side walls and being substantially parallel to the sensor substrate upper surface, the protuberance upper surface being configured to operably have a luminescent material optically coupled thereto which, on stimulation, emits light downwardly through the protuberance upper surface and into the protuberance, wherein the outer walls of the protuberances are oriented relative to the protuberance upper surface such that the side wall ( 711 ) of each protuberance is vertically displaced from the upper surface at an angle substantially equivalent to one quarter the sum of the critical angles of the luminescent material/substrate interface and the environment/substrate interface so as to specifically redirect the light emitted by the luminescent material through the protuberance upper surface and received into the sensor substrate at angles which are less than the critical angle of the luminescent material/substrate interface and greater than the critical angle of the medium/substrate interface, out of the sensor substrate and towards a detector ( 704 ) provided below the protuberance upper surface, the protuberances using total internal reflection to operably redirect the light.