This invention relates to a lighting system including at least one LED (Light Emitting Diode) array which has at least one LED connected to a circuit board (14); at least one heat sink (11) provided and connected to LED array (s); and an optical transmission waveguide element (15) composed of transparent or translucent material to guide the light to required components for illumination. The waveguide element (15) is arranged and configured so that the light entering the waveguide element enters at an angle that it impinges the boundaries of the waveguide element at an angle below the internal refractive angle of the waveguide element and is reflected back into the body of the waveguide element and transmitted along the length of the element. A combination of pre-determined waveguide cross section and outer edge rim detailing, may be used to create a tailored emitted lighting distribution at the waveguide outer edge. Multiple waveguides using the same or differing edge lighting distributions may be combined to produce an overall luminaire lighting distribution.
