Tadao Nakazawa

Driver-less 40 Gb/s LiNbO/sub 3/ modulator with sub-1 V drive voltage

We have succeeded in reducing the drive voltage of a 40Gb/s LiNbO/sub 3/ modulator to 0.9 V, which is the lowest-drive-voltage 40Gb/s LiNbO/sub 3/ 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.

A low DC-drift Ti:LiNbO3 modulator assured over 15 years

The use of the Ti:LiNbO3 modulator has begun in advanced optical transmission experiments (1) and it is planned for commercial optical transmission systems. There has, however, been no report to guarantee the long-term reliability of Ti:LiNbO3 devices against DC drift. DC drift is complicated by temperature and humidity. We prevented the temperature and humidity drift by employing a Si coating technique (1). We evaluated the long-term DC drifts of our modulator and confirmed that it is stable enough for use in commercial optical transmission systems.

Fully dynamic and reconfigurable optical add/drop multiplexer on 0.8 nm channel spacing using AOTF and 32-wave tunable LD module

We developed and confirmed the feasibility of a dynamic optical add drop multiplexer (OADM) system using an acousto optical tunable filter (AOTF) and a wavelength tunable LD module. A 4-concatenation transmission of this system was performed successfully.