We report on an LDRD seed program of novel technology development (started by an FY98 Engineering Tech-base project) that will enable extremely high-fidelity analog-to-digital converters for a variety of national security missions. High speed (l0+ GS/s ), high precision (l0+ bits) ADC technology requires extremely short aperture times ({approx}1ps ) with very low jitter requirements (sub 10fs ). These fundamental requirements, along with other technological barriers, are difficult to realize with electronics: However, we outline here, a way to achieve these timing apertures using a novel multi-wavelength optoelectronic short-pulse optical source. Our approach uses an optoelectronic feedback scheme with high optical Q to produce an optical pulse train with ultra-low jitter ( sub 5fs) and high amplitude stability (<10{sup 10}). This approach requires low power and can be integrated into an optoelectronic integrated circuit to minimize the size. Under this seed program we have demonstrated that the optical feedback mechanism can be used to generate a high Q resonator. This has reduced the technical risk for further development, making it an attractive candidate for outside funding.

Packaging of integrated optic modulators can be simplified if the electrodes are 50 ohms impedance. Recently built X-cut lithium niobate velocity matched modulators have a 50 ohm impedance. The interconnection of the modulators to external connectors by on-chip tapers is critical to there performance at frequencies in the 23 to 50 Ghz frequency range. The attachment of fibers to the modulators is being enhanced with work on a robotic machine that uses a combination of machine vision and active alignment to both coarse and fine position the fiber to the waveguide. The design goal is to have each fiber attached in under 2 minutes.