Liquid Phase Deposition of GeO2 Glass Hollow Waveguide for Delivery of CO2 Laser Radiation

CO₂ laser (wavelength 10.6 μm) has important applications in laser surgery, material processing, infrared sensors and imaging. CO₂ laser optical waveguides are gaining a central position in these applications. Glass-drawing technique and sol-gel methods have been used to prepare GeO₂ and germania-based glass hollow waveguides. In this work, a GeO₂ glass hollow waveguide sample was fabricated by using a liquid phase deposition (LPD) approach. The morphology, structure and optical transmission properties of the sample were studied. The results indicate that a GeO₂ glass reflective layer could be formed on the inner wall of a silica glass capillary tube via the LPD process. The GeO₂ glass layer and the substrate silica glass tube constitute an attenuated total reflectance (ATR) hollow waveguide structure. An nr<;1 band centering at around 10.6 μm is observed by loss spectrum analysis of the sample. The sample shows a mean loss of 1.13 dB/m for delivery of a ~35 W CO₂ laser beam (TEM00).