Patent ID: 7701630

Claim:
A Mach-Zehnder optical modulator comprising: a substrate of electro-optic material having a plurality of regions with alternating domain structure; a Mach-Zehnder (MZ) optical waveguide interferometer formed in the substrate and having two optical waveguide arms, the waveguide arms having a length so as to include at least four regions of alternating domain structure; an RF signal electrode including an RF input and an RF output, and having at least four sections, each section having a length substantially corresponding to the alternating domain structure regions of the substrate, the RF signal electrode positioned over sections of the two optical waveguides arms such that the signal electrode crosses from one optical waveguide arm to the other optical waveguide arm at a boundary of each alternating domain structure region; the lengths of the at least four RF signal electrode sections are predetermined to approximate a constant chirp versus frequency over an optimized frequency band, such that: the sections include a center section or center pair of sections disposed asymmetrically between an RF input and an RF output, and surrounded by one or more pairs of surrounding sections, the pairs of surrounding sections including an innermost surrounding pair of sections comprising two sections adjacent the center section or center pair of sections, and two sections adjacent the innermost pair of sections moving outwardly from the innermost to a final outermost pair at the RF input and RF output, the surrounding pairs having lengths that are equal to each other or unequal such that the section closer to the RF output is longer than the section closer to the RF input, the lengths of the surrounding pairs decreasing from the innermost surrounding pair to the outermost surrounding pair of sections.