Aspects of the subject disclosure may include, for example, obtaining two inputs x.sub.I and x.sub.Q based on a digital input signal, and causing a modulator to create two substantially orthogonal output dimensions I and Q based on the two inputs x.sub.I and x.sub.Q, by performing controlled introduction of a correlation between the two inputs x.sub.I and x.sub.Q for the modulator, and detecting a resulting output power of the modulator to facilitate operation of the modulator. Other embodiments are disclosed.

In a system for converting digital data into a modulated optical signal, an electrically controllable device, including a modulator having one or more actuating electrodes, provides an analog-modulated optical signal that is modulated in response to output data bits of a digital-to-digital mapping. A digital-to-digital conversion provides the mapping of input data words to the output data bits. The mapping enables adjustments to correct for non-linearities and other undesirable characteristics, thereby improving signal quality