Ultrafast optical devices for high-speed optical data links

The development of photonic devices for the next generation of optical networks is dependent on advances in ultrafast materials and in the success of waveguide devices comprised of these materials. This includes new methods of producing integrated-optical devices by innovative growth techniques or novel hybridization schemes. We describe aspects of the ultra-fast optical communications program at Georgia Tech that involve the development of hybridized and integrated-optical devices and devices for use in ultrafast optical data links. Two major components are under development: i) a tapered rib electro-absorption modulator that includes an integrated spot-size converter for hybridization with a passive silica-waveguide tapped delay line. This unique hybridized semiconductor/glass waveguide provides the basic building block of the transmitter multiplexer. ii) a quasi-phase matched multilayer AlGaAs waveguide designed for surface-emitted second-harmonic generation. This device provides an all-optical serial-to-parallel converter and thereby demultiplexes ultrafast optical data streams. We describe our recent advances in materials growth and waveguide design and the impact on the performance of these devices.