Attenuated total reflectance (ATR) GeO2 hollow infrared waveguides deposited from aqueous germanate ion solutions with different GeO2 concentrations

The attenuated total reflectance (ATR) hollow waveguides capable of transmitting CO₂ laser have attracted wide research interest due to its advantages of simple structure, no end reflection, small beam divergence and good transmission modes. In this work, GeO₂ ATR hollow waveguides for delivery of CO₂ laser radiations were fabricated via an acid-induced liquid phase deposition (LPD) process. GeO₂ hollow waveguide samples were deposited from acidic aqueous germanate ion solutions with different GeO₂ concentrations. The morphology, compactness and surface roughness of the LPD-derived GeO₂ ceramic film were examined by SEM. The crystalline structure of the film sample was determined using XRD. The low-loss window of the GeO₂ waveguide tube was observed by a FTIR spectrometer. We measured the transmission loss of the sample for delivery of a 10.6 μm TEM₀₀ CO₂ laser beam. The results show that the variations in loss are consistent with the quality change of the GeO₂ ceramic films grown in solutions at different concentrations.