III-nitride Wide Bandgap Semiconductors for Optical Communications

1. Carrier-effect phase shifters Optical waveguide port 1 signal signal l-selected signal out Multi-l signal in port 2 electrodes Switch control III-nitride Wide Bandgap Semiconductors for Optical Communications Project Concept Goals and Approaches Program Goals • Investigate optical properties of III-nitride wideband semiconductors in infrared wavelength region and explore their true potential for applications in fiber-optic communications • Design, develop and characterize fast-switchable optical wavelength routers using GaN/AlGaN for future all-optical packet switched optic networks • Build nano-structure integrated photonic circuit in III-nitride semiconductors • Train graduate and undergraduate students in photonic systems, optical waveguide design, nano-fabrication techniques and semiconductor device physics. • High-speed all-optical packet switch is a required function of future intelligent optical networks • Current optical switch using MEMs and thermal tuning of silicon optical waveguides are too slow for packet switching • III-nitride is transparent in optical communications wavelength windows • III-nitride semiconductor material is thermally and mechanically stable with the refractive index closely matches to the optical fiber • The refractive indices of III-nitride optical waveguide can be fast tuned through carrier injection • Integrated optical waveguide devices using GaN/AlGaN combination are realizable to perform nanosecond all-optic packet switch Technical Approach • Extend the application of III-nitride wideband semiconductor materials from blue & UV into fiber-optic communication windows in infrared. • Design single-mode optical waveguides using GaN/AlGaN combination • Using carrier injection to control and modulate refractive index without affecting waveguide transparency • Construct wavelength routors using array-waveguide -gratings based on index tunable GaN/AlGaN waveguides Optical Switch/Router Cross section 3-dB waveguide coupler Top view 051403