Abstract: A color wheel comprises a plurality of light filters mounted on a hub or other mounting surface for rotation. The outer circumferential edge of the filters extend radially beyond the outer circumferential edge of the mounting surface. The mounting surface is beveled at its outer circumferential edge. The filters are mounted by adhesive between each filter and the mounting surface. The adhesive extends into at least a portion of the area between the bevel and the filters. Color wheel assemblies comprise such color wheels mounted to a rotational motor. The outer circumferential edges of the filters are aligned with each other to the same radial distance from the central rotational axis. In certain exemplary embodiments the filters are wedge shaped, having contact with adjacent filters only at their radially outer periphery.

Abstract: An electro-optic device is disclosed for altering the density of charge carriers within an integrated optical waveguide. The device includes a substrate, and an integrated optical waveguide extending across the substrate with two doped regions being provided such that an electrical signal can be applied across the doped regions to alter the density of charge carriers within the waveguide. The doped regions can each include a plurality of doped areas spaced apart from each other along the length of the waveguide.

Abstract: An optical circuit device (1; 1′) has a substrate (6; 5′) with a surface (7; 7′) and a structural discontinuity (17; 17′) in the surface. The surface is provided with a light source (13: 13′) to emit light and a circuit element (15; 15′) whose performance is adversely affected by the incidence thereon of stray light emifted by the light source. To reduce optical cross-talk, the optical circuit device is provided with a barrier element (21; 21′) which is adapted to absorb light emitted by the light source. The barrier element is located in the structural discontinuity and is so positioned as to be able to absorb stray light embted by the light source The optical circuit device may be an optical transceiver having a laser diode and a photodiods.