Photonic miniaturization requires seamless integration of linear andnonlinear optical components to achieve passive and active functionssimultaneously. Among the available material systems, silicon photonics holdsimmense promise for optical signal processing and on-chip optical networks.However, silicon is limited to wavelengths above 1100 nm and does not providethe desired lowest order optical nonlinearity for active signal processing.Here we report the integration of aluminum nitride (AlN) films on siliconsubstrates to bring active functionalities to chip-scale photonics. UsingCMOS-compatible sputtered thin films we fabricate AlN-on-insulator waveguidesthat exhibit low propagation loss (0.6 dB/cm). Exploiting AlN's inherentPockels effect we demonstrate electro-optic modulation up to 4.5 Gb/s with verylow energy consumption (down to 10 fJ/bit). The ultra-wide transparency windowof AlN devices also enables high speed modulation at visible wavelengths. Ourlow cost, wideband, carrier-free photonic circuits hold promise for ultra-lowpower and high speed signal processing at the microprocessor chip level.
展开▼
