A daylighting system for use in a building including a louver array having a first longitudinal element, and a second longitudinal element spaced therefrom. At least one of the first and second elements has an asymmetrical profile, each of the first and second longitudinal elements has a bottom profile including a parabolic surface, portions of opposing surfaces of the first and second longitudinal elements define a compound parabolic concentrator profile having a non-horizontal centerline that is tilted upwards, and the array prevents line of sight therethrough. A louver for a daylighting system includes (i) a leading edge defined by a leading connecting surface disposed between a parabolic concentrator surface and a flat surface; and (ii) a trailing edge defined by a trailing connecting surface disposed between a lower compound parabolic concentrator profile, and an upper compound parabolic concentrator profile. A method for designing a louver profile is provided.