An apparatus, comprising: a memory; and a processor operatively coupled to the memory, the processor configured to: determine, during a calibration of a coherent optical transmitter, a set of parameters associated with each tributary channel from a set of tributary channels by sending a first signal to a digital signal processor to adjust a scale factor of that tributary channel from the set of tributary channels, the coherent optical transmitter having an optical modulator and the DSP operatively coupled to the optical modulator, the coherent optical transmitter configured to output an optical signal processed by the DSP and modulated by the optical modulator via the set of tributary channels, the set of tributary channels including a first tributary channel and a second tributary channel, the scale factor associated with a tap characteristic of a finite impulse response filter of the DSP, determine, during the calibration of the coherent optical transmitter, a power imbalance between the first tributary channel and the second tributary channel based on the set of parameters associated with the first tributary channel and the set of parameters associated with the second tributary channel, send a second signal to the coherent optical transmitter to adjust a set of operational settings of the coherent optical transmitter based on the power imbalance between the first tributary channel and the second tributary channel, such that the power imbalance between the first tributary channel and the second tributary channel is reduced. a memory; and a processor operatively coupled to the memory, the processor configured to: determine, during a calibration of a coherent optical transmitter, a set of parameters associated with each tributary channel from a set of tributary channels by sending a first signal to a digital signal processor to adjust a scale factor of that tributary channel from the set of tributary channels, the coherent optical transmitter having an optical modulator and the DSP operatively coupled to the optical modulator, the coherent optical transmitter configured to output an optical signal processed by the DSP and modulated by the optical modulator via the set of tributary channels, the set of tributary channels including a first tributary channel and a second tributary channel, the scale factor associated with a tap characteristic of a finite impulse response filter of the DSP, determine, during the calibration of the coherent optical transmitter, a power imbalance between the first tributary channel and the second tributary channel based on the set of parameters associated with the first tributary channel and the set of parameters associated with the second tributary channel, send a second signal to the coherent optical transmitter to adjust a set of operational settings of the coherent optical transmitter based on the power imbalance between the first tributary channel and the second tributary channel, such that the power imbalance between the first tributary channel and the second tributary channel is reduced. determine, during a calibration of a coherent optical transmitter, a set of parameters associated with each tributary channel from a set of tributary channels by sending a first signal to a digital signal processor to adjust a scale factor of that tributary channel from the set of tributary channels, the coherent optical transmitter having an optical modulator and the DSP operatively coupled to the optical modulator, the coherent optical transmitter configured to output an optical signal processed by the DSP and modulated by the optical modulator via the set of tributary channels, the set of tributary channels including a first tributary channel and a second tributary channel, the scale factor associated with a tap characteristic of a finite impulse response filter of the DSP, determine, during the calibration of the coherent optical transmitter, a power imbalance between the first tributary channel and the second tributary channel based on the set of parameters associated with the first tributary channel and the set of parameters associated with the second tributary channel, send a second signal to the coherent optical transmitter to adjust a set of operational settings of the coherent optical transmitter based on the power imbalance between the first tributary channel and the second tributary channel, such that the power imbalance between the first tributary channel and the second tributary channel is reduced.