Abstract

We have succeeded in reducing the drive voltage of a 40 Gb/s LiNbO₃. modulator to 0.9 V at 40-Gb/s modulation. This low drive voltage was achieved with using a new design concept that featured a wide-gap, long CPW electrode. This modulator can be driven by a low-cost Si process based IC without driver amplifiers.

We have succeeded in reducing the drive voltage of a 40Gb/s LiNbCb modulator to 0.9 V, which is the lowest-drive-voltage 40Gb/s LiNbCb modulator in the world. The modulator can be driven within the break down voltage of a SiGe transistor. This result was achieved using a new design concept that featured a wide-gap, long CPW (coplanar waveguide) electrode. This low drive voltage enables the integration of the logic ICs and driving circuits on one chip using SiGe technologies, which will dramatically reduce the cost, size, and power consumption of 40 Gb/s transmitters. Figure 1 shows eye diagrams of the driving signal and optical output in a PRBS 2 -1. A clear eye opening was obtained with a 0.9 V drive voltage. Figure 2 shows the progress in the performance of LiNbCb modulators. The performance of our modulator is more than two times superior to that of other modulators reported to date. Our 0.9 V drive voltage LiNbCb modulators will open up a wide range of applications for 40 Gb/s fiber optic links. Figure 1 Eye-diagrams of driving signal and optical output Figure 2 Progress of performance of LiNb03 modulators

© 2002 Optical Society of America