Abstract: An optical transmitter that determines and controls the extinction ratio of an optical signal by modulating the duty cycle of the optical signal. The transmitter obtains a signal from the monitor circuit that represents optical power emitted by the electro-optic transducer during normal conditions in which the duty cycle of the optical signal is between a bias high and bias low modulation condition. The transmitter also obtains a signal from the monitor circuit that represents optical power emitted during the bias high modulation condition in which the time at the optical high power level in the eye diagram is greater. Also, the transmitter obtains a signal that represents optical power emitted by the electro-optic transducer during the bias low modulation condition in which the time at the optical low power level in the eye diagram is greater. Based on these signals, the transmitter then derives the extinction ratio.

Abstract: Systems and methods for compensating transitions in a data stream to account for jitter including laser jitter. Transitions in the data stream are delayed or advanced depending on the laser jitter and/or whether the previous transition is a rising or falling transition. The compensation of transitions is non-linear such that compensation applied to a rising transition is not necessarily the same as compensation applied to a falling transition. A history of more than one or more bits or transitions of the data stream can be used to further adjust the compensation of transitions in the data stream. When a transition is detected, the bit following the detected transition is peaked either positively or negatively such that the following transition is accordingly delayed or advanced.