Optical output device and method for controlling an optical transmitter

摘要

Since it is difficult to emit a control a IQ modulator emitting modulated lightwave according to QAM format without signal degradation of said emitted signal due to low frequency dither used for the control of said modulator, a method for controlling an optical transmitter according to an exemplary aspect of the invention includes: generating a multilevel electrical signal by means of combining two or more binary electrical signals, where said multilevel signal is used to drive the modulator of adding a low frequency dither signal on several of the binary electrical signals, wherein the phase of the added dither signal depends on the value of the binary signal to which it is added; tapping a portion of light after the modulator and generating a monitor signal from the tapped light; controlling the modulator according to the monitor signal.

主权项

1. An optical output device comprising:
a combiner to combine a plurality of binary electrical signals and add a dither electrical signal having a frequency lower than a bit rate of the binary electrical signals to the binary electrical signals; an adjuster to adjust an amplitude of the binary electrical signals; and a modulator to modulate an optical signal based on the binary electrical signals, wherein the dither electrical signal has a phase based on a value of the binary electrical signals and that is susceptible to change based on each of a plurality of bits of the binary electrical signals.