Glass fiber waveguide made of anhydrous quartz glass with a reflecting silicone-rubber cladding

Waveguides were made with a core of anhydrous quartz glass and a cladding of silicone rubber. The glass was formed by electrical melting of high-purity cristobalite. The lowest optical losses in the waveguide at the wavelength 0.98 μ were 20 dB/km rising to 26 dB/km at the wavelength of 0.95 μ. It was found that the hydroxyl group content increased when the glass was drawn into a rod with the aid of a gas burner; however, when drawing was performed using CO₂ laser for heating, there was no change in the hydroxyl group content.