Abstract: Proposed is a waveguide which is formed on a substrate (2) of a polymer. For that purpose, provided between the substrate (2) and the waveguide layer (1) is an intermediate layer (8) of an inorganic material which prevents a substantial amount of energy from penetrating into the relatively highly absorbent polymer material. That minimises the waveguide losses.

Abstract: A color wheel includes a rotatable disc-shaped carrier to which three or more planar color filter segments are secured in radial fashion about the periphery thereof. The portions of the color filter segments extending beyond the peripheral portion of the carrier form a substantially continuous translucent color ring for being inserted into, and rotated through, a light path. Each of the color filter segments is formed of a continuous sheet of material without any apertures formed therein. The disc-shaped carrier has one or more recesses, or bonding zones, formed therein to receive innermost bonding portions of the color filter segments; these recesses provide stops for aiding in the proper radial and axial positioning of the color filter segments. The bonding portions of the color filter segments are secured to the bonding zone of the disc-shaped carrier by an adhesive. A further recess can be formed in the disc-shaped carrier adjacent each bonding zone to receive the adhesive layer.