Directly written photo-crosslinked fluorinated polycarbonate photoresist materials for second-order nonlinear optical (NLO) applications

A series of acrylate group terminated fluorinated polycarbonates containing 4,4-cyclohexylidenebis phenol (BPZ) (AF-Z-PC MAs) or dodecyl chains (AF-Ali-PC MAs) were synthesized. These polymers were further doped with chromophores and crosslinked under a UV lamp. With these doped polymers as the functional layer, we successfully obtained straight and Y structure waveguides by a direct writing method for electro-optical modulator devices. These cross-linked polymers displayed good thermal stability, low optical loss and a high refractive index. In addition, after polarization, the electrooptic coefficients r33 of the doped films were 10 pm V−1 and 9 pm V−1, measured by the Teng–Man method, respectively. The results showed that the direct writing method was a simple and effective way to fabricate Mach–Zehnder structure waveguides and these new macroacrylate terminated polycarbonates had great potential in the application of electro-optical modulator devices.