Abstract: The present invention relates to three dimensional photovoltaic structures and a power generation apparatus comprising same. The photovoltaic structure comprises a light transmitting solid optical core having a longitudinal axis, a top end, a bottom end and one or more side walls, wherein the top end has an exposed outer surface to receive light. a photovoltaic layer surrounds at least a portion of one or more of the side walls of the optical core and an optical cladding layer surrounds the photovoltaic layer.