ABSTRACT
This chapter discusses both quality control and diagnostic measurements for multimode fibers. It also discusses the quality control measurements of attenuation, bandwidth, and numerical aperture. The chapter describes how optical waveguide fibers are produced. The drawing of optical waveguide fibers requires that the root of the preform be heated from 1900 to 2200°C. There are many manufacturing processes for making single-mode and multimode fibers. The manufacturing process basically consists of four main operations. These are preform fabrication, fiber drawing, optical characterization and mechanical characterization. The transmitting medium, to a large extent, is the most important component in the optical fiber communication system. In preform fabrication, either one glass rod consisting of both the core and cladding is prepared, or glass materials for the core and the cladding are separately prepared. The use of boron in the optical core has resulted in increased absorption at wavelengths greater than 1300 nm.
