Mach-Zehnder optical modulator
AssigneeJDS Uniphase Corporation
InventorMalcolm Green
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Abstract
The present invention relates to a Mach-Zehnder optical modulator having an electrode structure that is arranged to compensate for temperature induced performance degrading variations. The distances between appropriate faces of the signal electrode and a ground electrode and corresponding wave-guide arms are arranged such that there is a more balanced thermal expansion of the waveguide arms due to heating of the waveguides by the RF signals carried on the signal and ground electrodes. Tailored buffer layers further balances the heating in the waveguide arms through the RF losses in the electrodes. The balanced heating reduces the temperature gradient between the waveguide arms of the optical modulator and hence reduces the adverse thermally induced performance degrading variations.
Claims14
An optical modulator comprising an input waveguide and an output waveguide coupled by first and second waveguide arms, the first and second waveguide arms having an electrode structure, comprising at least three electrodes asymmetrically disposed relative to the first and second waveguides, at least two of the electrodes are positioned such the distance between a first electrode of the two electrodes and the first waveguide is substantially equal to the distance between a second electrode of the two electrodes and the second waveguide.
An optical modulator comprising an input waveguide and an output waveguide coupled by first and second waveguide arms, the first and second waveguide arms have respective electrode structures comprising at least first and second electrodes for applying a modulating signal to the waveguide arms, the first and second electrodes being positioned on respective, separate, buffers;
- the buffers having dimensions such that the thermal coupling between the electrodes and the waveguides is substantially equal.
Dependencies are inferred from the claim text.