DARPA creates microchip with 50m of coiled optical waveguides 11/29/2013 - 00:00 DARPA's iPhoD program reaches successful conclusion with demonstration of low signal loss records with microchip-scale, integrated waveguides for photonic delayLong coils of optical waveguides any structure that can guide light, like conventional optical fiber can be used to create a time delay in the transmission of light. Such photonic delays are useful in military application ranging from small navigation sensors to wideband phased array radar and communication antennas. Although optical fiber has extremely low signal loss, an advantage that enables the backbone of the global Internet, it is limited in certain photonic delay applications. Connecting fiber optics with microchip-scale photonic systems requires sensitive, labor-intensive assembly and a system with a large number of connections suffers from signal loss. DARPA-funded researchers developed new methods to integrate long coils of waveguides with low signal loss onto microchips potentially enabling a leap ahead in size reduction and performance.DARPA's integrated Photonic Delay (iPhoD) program created a new class of photonic waveguides with losses approaching that of optical fiber. The new waveguides are built onto microchips and include up to 50 meters of coiled material that is used to delay light. Conventional fiber optic coils of the same length would be about the size of a small juice glass. These waveguides also employ modern silicon processing to achieve submicron precision and more efficient manufacturing. The result is a new component that is smaller and more precise than anything before in its class.
