Formation of slab waveguides in eulytine type BGO and CaF2 crystals by implantation of MeV nitrogen ions

Ion implantation, compared with other waveguide fabrication methods, has some unique advantages. It has proved to be a universal technique for producing waveguides in most optical materials. The authors of the present article reported fabrication of channel and slab waveguides in an Erbium-doped tungsten tellurite glass by implantation of MeV energy N+ ions. The present article reports successful adaptation of the same technique to the fabrication of slab waveguides in eulytine type bismuth germanate (BGO) and CaF2 crystals. This is the first report on successful waveguide fabrication in these materials using 3.5 MeV N+ ions at implanted fluences between 5 × 1015 and 4 × 1016 ions/cm2. Spectroscopic ellipsometric measurements revealed the existence of guiding structures in both materials. M-line spectroscopic measurements indicated guiding effect in the as-implanted BGO up to 1550 nm and up to 980 nm in the as-implanted CaF2. Ion implantation induced the appearance of three peaks in the UV/Vis absorption spectrum of CaF2, that can be attributed to colour centres.