Modulator driver for driving an electro-optical modulator in a high-speed optical communications system. In accordance with aspects of the present invention, a modulator driver is presented comprising an input differential limiting amplifier which is coupled to a distributed differential current-switch configuration, where one set of outputs of the distributed differential current-switch configuration are grounded and the other set of outputs are connected to an artificial transmission line structure generating forward traveling and reverse traveling signals, with the reverse traveling signal termination bias inductively coupled to a separately adjustable positive bias voltage, whereby the circuit architecture reduces the number of components and transitions in the high-speed signal path and is compatible with compact, monolithic fabrication requiring a minimal amount of external components for operation. Other methods and apparatus are presented.