CIPS/OSA Brown Bag Seminar Series

Thursday, November 15, 2007

12 noon , RLE Haus Conf. Room 36-428

"Photonic Integrated Circuits for Optical Logic"

Ryan Williams

This talk will discuss integration schemes for photonic integrated circuits, with an emphasis on optical logic applications. Our optical logic unit cell is the photonic analog to transistor-transistor logic in electronic devices. Active devices such as InP-based semiconductor optical amplifiers (SOA) emitting at 1550 nm have been vertically integrated with passive waveguides using the asymmetric twin waveguide technique and the SOAs are placed in a Mach-Zehnder interferometer
(MZI) configuration. By sending in high-intensity pulses, the gain characteristics, phase-shifting, and refractive indices of the SOA can be altered, creating constructive or deconstructive interference at the MZI output. Boolean logic and wavelength conversion can be achieved using this technique, building blocks for optical switching and signal regeneration.

The fabrication of these devices is complex and the fabrication of two generations of devices is described in this talk, including optimization of the mask design, photolithography, etching, and backside processing techniques. Testing and characterization of the active and passive components will also be discussed.