Electroptic Polymer Linear Modulators Based on Multiple-Domain Y-Fed Directional Coupler

We developed an analytical method to optimize the design of Y-fed direction couplers at large modulation depth from 10% to 50%. Simulation results indicate that three and four-domain devices can obtain 45 dB higher distortion suppression than two-domain devices, which can potentially achieve 120 dB spurious free dynamic range. We also experimentally demonstrated that the two-domain electrooptic modulator obtained 94 dB distortion suppression at 20% modulation depth, which is 47 dB higher than a conventional Mach-Zehnder modulator.