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, a center line of the compound parabolic concentrator profile is non-horizontal and is tilted upwards, and the array prevents line of sight therethrough. A louver for a daylighting system includes (i) a leading edge defined by an intersection of a parabolic concentrator surface, and a flat surface; and (ii) a trailing edge defined by an intersection of a lower compound parabolic concentrator profile, and an upper compound parabolic concentrator profile. A method for designing a louver profile is provided.