Optical Circuits Developed with Semiconductor Diamonds

Wolfram Pernice (Karlsruhe Institute of Technology)

Engineers at Karlsruhe Institute of Technology and colleagues in Germany developed an economical method to harness polycrystalline diamonds for optical circuits. The team led by nanotechnology lab director Wolfram Pernice published its findings earlier this week in the journal Nature Communications (paid subscription required).

Optical circuits work like integrated electronic circuits, but instead of transmiting data with electrons, optical circuits use light-transmitting particles known as photons. Like electronic circuits, optical circuits are applied in wafers, in this case ultra-thin nanoscale flims. Optical circuits are often desirable for biomedical sensors, such as those used in fluorescence imaging.

Diamond material is transparent to light, including visible wave lengths, and well known for its strength and toughness. Previous methods to adapt diamond to optical circuits require the use of monocrystalline diamonds in the form of highly pure crystals, which because of their cost, are small in size and use sophisticated fabrication techniques.

Polycrystalline diamonds, on the other hand, have a more irregular crystal structure, but still exhibit the same robustness and ability to conduct photons as monocrystalline diamonds. Because of their relative impurity in structure, they are lower in cost and can be applied in a larger area.

Pernice’s team, which included colleagues at the Fraunhofer Institute for Applied Solid State Physics in Freiberg, Germany and Diamond Materials GmbH, a spin-off company from the Fraunhofer Institute also in Freiberg, fabricated optomechanical circuits that combine optics with mechanical elements, in this case nanoscale resonators that vibrate in reaction to certain frequencies.

Pernice and colleagues fabricated nanoscale optomechanical circuit wafers using a vapor deposition technique. “In our study,” says Patrik Rath, the paper’s first author, “we have made use of the fact that today, nanophotonic components can be manufactured in the same sizes as nanoscale mechanical resonators. When the resonator responds, corresponding optical signals are transferred directly to the circuit.”

Rath notes as well that “Nanomechanical resonators are among today’s most sensitive sensors and are used in various precision measurements.” Pernice adds, “The elements thus manufactured that is, the resonators, circuits, and the wafer, are attractive because of their high quality.”

Read more:

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• Grant Funds Feasibility Study of Photonic Ethernet Chips
• International Team Develops Optical Packet Router

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