Highly linear electrooptic modulator with suppression of even-order distortions

The distortion introduced by a Y-junction directional coupler modulator (Y-DCM) on an analog optical link is analyzed and compared to that of a Mach-Zehnder (MZM) and of a directional coupler (DCM) modulators. The results reveal that a specific configuration of the Y-DCM allows to bring together advantages of suppressing even-order distortions, similar to that of a MZM, and of enabling high spurious free dynamic range, around 126 dB.Hz4/5, similarly to that of a DCM.