Fabrication of mid-infrared planar waveguides from compatible fluorozirconate glass pairs, via hot spin-casting

As there is a current demand for mid-infrared (IR) optical components an in vestigation was conducted to assess the possibility of producing planar, fl uorozirconate glass waveguides. A series of ZBLANP [ZrF4-BaF2-LaF3-AlF3-NaF -PbF2] glasses was constructed by increasing substitution of BaF2 by PbF2. Glass samples were cast from the liquid for optical assessment purposes. Th e refractive index of these glasses was measured to an accuracy of +/-0.3% using the minimum deviation technique. The refractive index was measured at 632.8 and 3390 nm. A pair of glasses was selected for production of a mid- IR planar waveguide to achieve the necessary numerical aperture (NA) for gu iding at 3-5 mum. Using a hot spin-casting technique, combined with photoli thography. a basic ridge guide of cross-section 50 x 50 mum was fabricated and the ends were polished and were examined using optical microscopy for r oughness and shape. Optical guiding was demonstrated within the guide at 63 2.8 nm. (C) 2001 Elsevier Science B.V. All rights reserved.