Abstract

We have studied a new class of thermosetting nonlinear optical polymers for electrooptic (EO) devices. The new material is a two-component system that is mixed just before thin film spin-coating. After thermal polymerization at elevated temperature, a fully cross-linked polymer network is obtained with disperse red nonlinear active groups covalently connected to the polymer backbone. Thin films from 0.1 to 5 µm thick with good optical qualities can be obtained from spin-coating. The polymer films are rigid and chemical resistant. From our second-harmonic generation (SHG) measurement, the resonance enhanced d₃₃ coefficient was ~ 140 pm/V at 1.06-µm fundamental wavelength. With a Mach-Zehnder interferometer, the EO coefficient r₁₃ = 14 pm/V was measured at 633-nm wavelength with 3-kHz modulation frequency, in good agreement with that derived from SHG d₃₁(d₃₁ = d₃₃/3) coefficient with two-level model. Compared with other fully crosslinked polymer systems, this relatively large value results from the incorporation of non-linear groups of higher hyperpolarizabity.

© 1991 Optical Society of America