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Short-path-length resonant-type high-speed optical modulators are presented. To reduce the active electrode length and enhance modulation efficiencies, different types of resonant electrode structures were investigated using computer simulation tools. Electrical power coupling into the resonators was optimized with a variety of power-feeding circuits. Their resulting optical and electrical behaviors are compared with measurements on modulators fabricated in Ti:LiNbO3. As a result, resonant-type optical modulators are presented that achieve a low voltage-length product of 25 V mm at 30 GHz in the 1.55-μm wavelength range. Fiber-to-fiber loss of a fully packaged phase modulator with an active optical path length as short as 0.7 mm was 2.3 dB [ABSTRACT FROM PUBLISHER]

Frequency dependent drive voltage is reported in velocity matched, packaged, Mach-Zehnder interferometers, made on Z-cut, Y-propagating LiNbO3, with and without etched ridges. Drive voltages of ~7 V at 40 GHz are demonstrated, with the etched ridge device showing a 1/2-1 V advantage. Microwave modeling allowed the extraction of the effects of dispersion in material properties, occurring near the acoustic resonance, on bandwidth and drive voltage [ABSTRACT FROM PUBLISHER]

A reflection traveling-wave LiNbO3 modulator is used to demonstrate unamplified link gain to 550 MHz, taking advantage of its low-drive voltage (0.5 V Vπ) at low frequencies, and high optical powers. 7.5 dB of gain is achieved at 50 MHz with an optical power of 188 mW and 8.5 mA of detector current. Noise figure of the 50-MHz link is it dB and spur-free dynamic range is 114 dB·Hz2/3. A model for gain is presented, which shows good agreement with experimental results [ABSTRACT FROM PUBLISHER]