An optical device, comprising: a transmitter to provide an optical signal via a set of channels; and a modulator comprising: two or more tributary modulators (306-1, 306-M) to modulate an X polarization channel, X channel, of the set of channels, and a Y polarization channel, Y channel, of the set of channels, with a training pattern, the X channel including an in-phase channel, XI channel, of the set of channels, and a quadrature channel, XQ channel, of the set of channels, the Y channel including an in-phase channel, YI channel, of the set of channels, and a quadrature channel, YQ channel, of the set of channels; a set of optics to alter a first channel, of the set of channels, relative to a second channel of the set of channels to cause the first channel to destructively interfere with the second channel; a detector to determine an optical power measurement of the optical signal after the first channel is caused to interfere with the second channel; and a controller to: generate a control signal to adjust a power balance associated with the optical signal based on the optical power measurement; and provide the control signal to a tributary modulator, of the two or more tributary modulators, to alter a modulation of the optical signal. a transmitter to provide an optical signal via a set of channels; and a modulator comprising: two or more tributary modulators (306-1, 306-M) to modulate an X polarization channel, X channel, of the set of channels, and a Y polarization channel, Y channel, of the set of channels, with a training pattern, the X channel including an in-phase channel, XI channel, of the set of channels, and a quadrature channel, XQ channel, of the set of channels, the Y channel including an in-phase channel, YI channel, of the set of channels, and a quadrature channel, YQ channel, of the set of channels; two or more tributary modulators (306-1, 306-M) to modulate an X polarization channel, X channel, of the set of channels, and a Y polarization channel, Y channel, of the set of channels, with a training pattern, the X channel including an in-phase channel, XI channel, of the set of channels, and a quadrature channel, XQ channel, of the set of channels, the Y channel including an in-phase channel, YI channel, of the set of channels, and a quadrature channel, YQ channel, of the set of channels; a set of optics to alter a first channel, of the set of channels, relative to a second channel of the set of channels to cause the first channel to destructively interfere with the second channel; a detector to determine an optical power measurement of the optical signal after the first channel is caused to interfere with the second channel; and a controller to: generate a control signal to adjust a power balance associated with the optical signal based on the optical power measurement; and provide the control signal to a tributary modulator, of the two or more tributary modulators, to alter a modulation of the optical signal. generate a control signal to adjust a power balance associated with the optical signal based on the optical power measurement; and provide the control signal to a tributary modulator, of the two or more tributary modulators, to alter a modulation of the optical signal.