Polymer waveguide grating fabricated by two-photon initiated photopolymerization and its application as an input coupler

Two-photon polymerization, initiated by 1-[(1E)-2-(4-{[4-((1E)-2-{4-[4-N,N-di-methylamino]phenyl}vinyl)phenyl]phenylamino}phenyl)vinyl]-4-[4-N,N-di- methylamino]benzene, is employed to fabricate volume index gratings in polymer waveguide. We demonstrate the implementation of input coupling by this grating into the polymeric waveguide film at 632.8 nm wavelength. A simple approach to measure the refractive index and thickness of the polymer waveguide through the grating coupler is presented. The calculated refractive index and thickness are 1.51 and 1.99 μm, respectively.