Excimer laser inscribed submicron period relief gratings in InOx films and overlaid waveguides

Relief gratings of submicron periodicity are patterned in InOx thin oxide films using 248 nm interferometric excimer laser ablation. The ablation process is studied in terms of grating depth versus exposure conditions, using optical diffraction efficiency measurements. Real time monitoring of grating growth and film resistivity during grating writing are also presented. To study the exact grating morphology, scanning electron microscopy and atomic force microscopy microscans of the machined structures are performed. A discussion on the ablation behavior of InOx thin films is given in accordance with the experimental data obtained. Relief gratings are patterned in InOx thin films overlaid on ion-exchanged channel waveguides, and reflection spectra are also reported.