A BEAMSHAPING OPTICAL STACK, A LIGHT SOURCE AND A LUMINAIRE

摘要

A beamshaping optical stack (108), a light source and a luminaire is provided. The beamshaping optical stack (108) is to be optically coupled to a light emitting surface of a light emitter. The beamshaping optical stack (108) comprises a first light transmitting layer (120) and a second light transmitting layer (118). The second light transmitting layer (118) comprises a first side (110) which is optically coupled to the first light transmitting layer (120) to receive light from the first light transmitting layer (120). The second light transmitting layer (118) further comprises a second side (106) which is substantially opposite the first side (110) to emit the received light into another optical medium. The second light transmitting layer (118) further comprises a geometrical structure (116) at the second side (106) to obtain a decreasing light emission with increasing light emission angles (9a) with respect to a normal (112) to the first side (110). The first light transmitting layer (120) is of a first material having a first refractive index. The second light transmitting layer (118) is of a second material having a second refractive index. The first refractive index is lower than the second refractive index.