Time-Division Multiplexing/Demultiplexing and Data Encoding Experiments Using Fast T:LiNbO3 Directional Coupler Switch/Modulators

For multi-gigabit/sec communication systems, high-speed electro-optic guided-wave modulators and switches are attractive alternatives to circumvent spectral and optical power limitations of directly modulated semiconductor lasers. These waveguide devices may be used, for example, to externally modulate and time-division multiplex/demultiplex high peak power pulses obtained from mode-locked semiconductor laser sources. Here, we report fully-connectorized and packaged, 2X1 and 3X1 Ti:LiNbO3 waveguide switches designed for 1.3 μm wavelength and experiments carried out to assess the high-speed performance of these devices in optical time-division multiplexing/demultiplexing and data encoding applications. Using the devices as switches, we have actively multiplexed optical pulse streams with output non-return-to-zero (NRZ) center-to-center bit spacings of less than 100 ps, while incurring an average optical power penalty of only 0.5 dB. We have also operated the devices as modulators to encode a pseudo-random data stream at 2Gb/s NRZ without degradation of the eye pattern or the cw semiconductor laser source spectrum.