R.C. Williamson

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The general configuration of the proposed high-speed ADC was described. A train of optical pulses samples the analog signal applied to the optical modulator. A dual-output Mach-Zehnder electro-optic modulator is used to implement phase-encoded optical sampling. Output circuits detect and integrate the modulated optical pulses. The integrated level is held(More)
This letter describes a demonstration of a photonic analog-to-digital converter operating at 208 MS/s and utilizing phase-encoded optical sampling to achieve an 87-dB two-tone third-order intermodulation-free dynamic range. A pair of LiNbO/sub 3/ 1-to-4 optical time-division demultiplexers with >35-dB channel extinction distribute the 30-ps sampling pulses(More)
Mach-Zehnder interferometer thermooptic switches were made using a thin-silicon-on-insulator material system. The switches use single-mode strip-Si waveguides, 0.26/spl times/0.4 /spl mu/m, operating at 1.5 /spl mu/m. The waveguides were heated directly by passing current through them, resulting in switching power of 6 mW, and a rise time of 0.6 /spl mu/s.(More)
In parallel with the development of fiber optics for transmission of digital information, the 1970s and 1980s saw the development of techniques for the transmission of wide-bandwidth analog radio-frequency (RF) signals over optical fibers. The simultaneous need for high linearity and high signal-to-noise in RF photonic links spurred the development of(More)
Progress in the development of high-speed electrooptic A/D converters is reviewed. A/D converters of this type have been operated at 1 gigasample/second (GS/s) in 2- and 4-bit structures for 500-MHz analog bandwidth. The converter consists of an array of LiNbO<inf>3</inf>guided-wave interferometric modulators that function as an analog amplitude analyzer,(More)
The use of reflective arrays in surface-wave devices has yielded new devices such as resonators in addition to an enlarged parameter range for devices such as radar pulse expanders and compressors. A number of different grating geometries, substrates, and types of reflectors have been employed in resonators, band-pass filters, filter banks, oscillators, and(More)
The combination of phase-encoded optical sampling and optical time-division demultiplexing has been demonstrated to extend the performance of electronic analog-to-digital converters (ADCs). We report a 10-effective-bit, 505-MS/s ADC with a spur-free dynamic range in excess of 70 dB.
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