Effect of substrate temperature on the properties of carbon-coated optical fibers prepared by plasma enhanced chemical vapor deposition

摘要

The effect of substrate temperature on the properties of carbon-coated optical fibers prepared by plasma enhanced chemical vapor deposition is studied. The substrate temperatures were set at 20, 150, 300, and 450 ℃. The deposition rate of carbon films decreases with increasing substrate temperature, while the self-bias voltage during deposition increases. The results of analysis by Fourier transform infrared spectroscopy and determination of the optical band gap show that sp~2 carbon sites in the coating structure increase as the substrate temperature increases. When the substrate temperature changes from 20 to 300 ℃, the carbon coating surface becomes more compact. Alternatively, when the substrate temperature is increased to 450 ℃, many nano-scale hillocks appear on the carbon coating surface. The carbon coating prepared at the substrate temperature of 300 ℃ has the highest water contact angle of 90° and an excellent ability to sustain the thermal loading, so it is the best for production of carbon-coated optical fibers.