Abstract

Interest in optical modulators and switches that operate at the highest possible electrical drive frequencies continues to be motivated by potential applications in optical communication and signal processing and consequently also in test instrumentation for optical network analysis and optical sampling. In all cases a low drive voltage for large optical modulation depth is desirable and often essential. Here we report the low voltage operation at millimeter-wave frequencies of a four-port Ti:LiNbO₃ balanced-bridge Mach-Zehnder switch/modulator for a 1.3-μm wavelength. The device makes use of periodic phase-reversed traveling-wave electrodes to ameliorate the effects of the difference, or mismatch, of the electrical and optical velocities in LiNbO₃.¹ We demonstrate that the switch requires only 407 mW of electrical drive power for full on-off modulation at 36 GHz making it suitable as a 72-Gbit/s binary multiplexer/demultiplexer.

© 1990 Optical Society of America