Optimized curing process for perfluorinated acrylic polymer optical waveguide

UV polymerization of perfluorinated acrylic polymer (ZPU12) for optical waveguide is studied by FTIR spectroscopy. With 15 μm planar thickness of the polymer material ZPU12-450 and 6 μm thickness of ZPU12-456 requires 8 and 3 min repectively to be fully UV cured with low intensity of 14 mW/cm2 at room temperature in the presence of nitrogen flowing. These results show the delay of curing reaction with increasing thickness or depth in the optical waveguide. Besides, a thickness of 6 μm of ZPU12-456 requires about 4 min to be fully UV cured with intensity of 12 mW/cm2. The conversion rate slows down on the decreasing of curing intensity. The polymerization also shows that the UV induced polymerization is faster than thermal curing reaction. The refractive indices of ZPU12-450 is around 1.450 and most of the refractive indices of ZPU12-456 are between 1.455 and 1.456. On the other hand, the thermooptic coefficient of ZPU12-456, dn/dT is −2.105×10−4/°C and −2.090×10−4/°C for TE and TM polarization, respectively. The thermooptic coefficient of ZPU12-450, dn/dT is −2.737×10−4/°C and −2.465×10−4/°C for TE and TM polarization, respectively.