A prefabricated material that can be used to pull an optical fiber. Optical fiber prefabricated rod is the core raw material for the manufacture of quartz series optical fiber.Large-core preform is a kind of preform specially designed and developed for the field of energy transmission and sensing. This series of preforms are prepared by in-tube chemical vapor deposition process, which has the advantages of high numerical aperture and good geometric uniformity. This series of products are widely used in laser energy transmission, data communication and other energy transmission, sensing and other fields.