Made of high-purity crystal, the quartz rings are manufactured into rough material by H2-O2 flame fusing. Its SiO2 content is more than 99.9999%, and it is clear and bubble free. It is washed and shaped under strict control, and thus enjoys homogeneous density and free of suspended substances and other impurities. The cross section of the ring is rectangular, which makes it suitable for long term vapour deposition of multi-layer optical films. The quartz ring is a whole piece, so it may be evaporated evenly when heating by the electron gun. Thus, it may achieve films of even thickness and homogeneity. Therefore, quality of the optical films are improved and may reach the Class I quality requirements for pr閏ised optics. It could be used widely for vapour deposition of AR films and multi-layer films which request the highest surface precision in the world optics industry.