SUNLIGHT-BASED LARGE AREA LIGHT SOURCE AND LARGE AREA LUMINAIRE

A light source (25) for emitting collimated light (29) in particular for a large area luminaire (21) comprises a light guide unit (43) for guiding light by total internal reflection. The light guide unit comprises a plurality of localized light source regions (57) at a main front face (55A) for having light pass there through. The light source (25) further comprises a plurality of light emitting units (41) for emitting light into the light guide strips (91) through respective portions of the at least one coupling face (47) of the light guide unit (43), and a collimation unit (45) extending along the main front face (55A) and comprising a plurality of collimating elements. At least one light emitting unit (41) is configured as a light input coupling assembly (250) to receive collected natural light from a fiber (249) and to provide the received natural light to the light guide unit (43). The light source (25) can be implemented in a sunlight-based illumination system (241) collecting and providing natural light to the light source (25).