Investigations on short-path-length high-speed optical modulators in LiNbO3 with resonant-type electrodes

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 wa s optimized with a variety of power-feeding circuits. Their resulting optic al and electrical behaviors are compared with measurements on modulators fa bricated 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 GH z in the 1.55-mum 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.