Traveling wave electro-optic phase modulator using cross-linked nonlinear optical polymer

We report the fabrication and characterization of a high frequency traveling wave electro-optic phase modulator made from thermally cross-linked polyurethane-Disperse Red 19 polymers. The device has been fabricated using a three layer structure with an integrated 50 Ω microstrip line circuit. The straight channel optical waveguides were defined laterally by standard photolithography and oxygen reactive ion etching. The measured half-wave voltage was in good agreement with that extrapolated from the second harmonic generation measurements. Optical modulation was observed directly on a spectrum analyzer up to 18 GHz. Long-term evaluation over an extensive length of time found no observable loss of performance.