An integrated modulator of the Mach-Zehnder type includes two optical arms containing waveguides with PN junctions and biasing circuits for reverse biasing the PN junctions in response to a control signal. The two optical arms are situated within a semiconductor substrate of a first element that also has an interconnection region. The biasing circuits are situated, in part, within a substrate of a second element that also contains an interconnection region. The first and second elements are rigidly attached to each other via their respective interconnection regions.