Patent ID: 7394949

Claim:
An optical device, comprising: a first phase modulator positioned along a branch waveguide of a mach-zehnder interferometer, the first phase modulator including an n-type region having a proximity to a p-type region that causes a depletion region to form when a bias is not applied to the first phase modulator, the depletion region being at least partially positioned in a light signal carrying region of the waveguide; the first phase modulator being one of a plurality of phase modulators positioned along the branch of the mach-zehnder interferometer; and electronics configured to apply bias signals to each of the phase modulators such that each phase modulator receives a different one of the bias signals, the electronics providing delay between the application of the bias signals to different phase modulators, the delay synchronizing the light signal and the bias signals so each bias signal results in modulation of the same portion of the light signal.