An optical device is disclosed including: a non-imaging secondary concentrator having an entry aperture and an exit aperture, and configured to receive light focused by a primary focusing element from a source onto the entry aperture. The non-imaging secondary concentrator includes: a first portion proximal the entry aperture; and a second portion proximal the exit aperture which is not rotationally symmetric about an optic axis. The optical device further comprises a means for homogenizing the light focused onto the entry aperture of the secondary concentrator.