Photonic Integrated Circuits (PICs) can transmit information for computing using light rather than electricity. Using PICs on chips would allow for faster data transmission rates, lower power consumption, and less energy wasted through thermal dissipation. Diamond is a promising material for PICs due to its optical properties, however, fabrication difficulties have impeded progress in this area.

Researchers at the University of Pennsylvania have developed a new fabrication method for diamond waveguides that could be integrated with standard CMOS processing. This would allow easier integration of photonic elements with standard integrated circuits. The fabrication technique surrounds a high refractive index material (diamond) with a low index material (SiO2), with an additional intermediate index cladding (Si3N4) over the top of the waveguide. This geometry and composition produces full confinement of a single optical mode in the waveguide.

Difficulties associated with the current diamond-on-insulator approach are avoided with this new fabrication technique. Crucially, this waveguide structure is much better suited that the prior art to integration with CMOS processing, allowing photonic and electronic devices to be easily fabricated on the same chip. Producing a highly confined single mode waveguide with fewer fabrication issues than the prior art would be of great value in this emerging area.

• Compatibility with CMOS components
• Easier scaling and manufacturing of photonic components