Yes Oz the approach is definitely something that INTEL sees as beneficial and looks like a "first kick at the can" with no determination of material set.  POET (BB Photonics) has of course locked down the material set to include athermal capability and insertion with well-defined mode matching capability. The Intel patent definitely recognizes the advantages of moving away from silicon waveguides. This patent represents a substantial supporting document on how POET has achieved optical integration. Nice find Oz! We have a big lead and the design has been perfected and protected.

Below are a couple of relevant statements from the INTEL patent.

0016] The interposer 105 may include a dielectric substrate, for example, comprised of a dielectric material such as silicon dioxide glass, sapphire crystal, quartz crystal, or other dielectric materials that may be suitable for use as a carrier wafer for mounting electronic devices, photonic devices, and waveguides thereon. The optical waveguide 130 may include a silicon nitride material grown on a surface of the interposer 105, although this should not be construed as limiting, as the optical waveguide 130 may include other materials capable of guiding light between the photonic integrated circuits 120, 125. In some embodiments, the optical waveguide 130 may include an organic dielectric material, for example, a polymer. In other embodiments, the optical waveguide

130 may include other inorganic dielectric materials. The optical waveguide 130 may optically couple with the photonic integrated circuits 120, 125 using at least one microlens. The at least one microlens may include a same material as the optical waveguide 130, e.g., silicon nitride.

[0019] One advantage of using a silicon nitride optical waveguide 130 disposed on a surface of the interposer 105 to optically couple the photonic integrated circuits 120, 125 vs. using a silicon waveguide is reduced optical propagation loss of the silicon nitride optical waveguide 130 (e.g., < 0.5 dB/cm) compared to a silicon waveguide (e.g., approximately 2 dB/cm). Due to the relatively high propagation loss of a silicon waveguide, e.g., on a silicon photonics chip, its routing distance may be limited to less than about 2 cm. Because of its much lower propagation loss, a silicon nitride optical waveguide 130 on the interposer 105 may have a much longer achievable routing distance than a silicon waveguide on a silicon photonics chip. The silicon nitride optical waveguide 130 may also have lower coupling loss with the photonic integrated circuits 120, 125 compared to a silicon waveguide. In addition, the optical waveguide 130 may provide a smaller form factor than fiber routing to optically couple the photonic integrated circuits 120, 125. For example, the silicon nitride optical waveguide 130 may have a bend radius less than about 5 mm, whereas an optical fiber may have a minimum bend radius of about 2 cm.