Inscription of Quasi-Sinusoidal Surface Relief Optical Gratings in ZEONOR™ Cyclic Olefin Polymer by a 10.5 MeV N4+ Ion Microbeam at Low Implanted Fluences

Direct writing of microstructures in ZEONOR™ cyclic olefin polymer, using a high-energy medium-mass ion microbeam, was proposed and demonstrated. Microbeams of 10.5 MeV N4+ ions were used. The implanted fluences were between 2.5·1012 and 2.0·1013 ion/cm2. The microstructures were surface relief optical gratings of quasi-sinusoidal profile and grating constant of 4, 8 and 16 µm. Peak-to-peak amplitudes of the gratings ranged from 10 to 90 nm. Measured profiles of the gratings were Fourier-analyzed. Highest measured net first-order diffraction efficiencies were between 25 and 29% at wavelengths of 405 and 640 nm, very close to the theoretical maximum of 33%, calculated with the Raman-Nath equation. This method could be used for the production of micro- and nanostructures in cyclic olefin polymers and copolymers and other polymers as well, either for the direct production of label-free biosensors and other devices, or to produce masters for hot stamping of such structures.