A Mach-Zehnder ring modulator includes a first optical path having a first diode and a optical path having a second diode. Each of the first and second diodes operates responsive to a voltage signal by modifying a phase of a light signal. A first optical coupler provides first and second light signals to the first and second optical paths, respectively. A second optical coupler couples outputs from the first and second optical paths. A feedback path is coupled between an output of the second optical coupler and an input of the first optical coupler.