ABSTRACT
A variety of passive fibre optic devices are used in optical fibre communication systems to perform specific tasks. Passive devices split, redirect, or combine light waves. This chapter describes in detail some common passive fibre optic devices. The simplest passive fibre optic devices are couplers. Couplers direct multiple input light waves to multiple outputs. The chapter explains other passive devices, such as wavelength division multiplexers and de-multiplexers, filters, circulators, and isolators. The design of polishing D-Section couplers involves embedding fibre cables into a solid material such as plastic. Mach—Zehnder interferometers are used in a wide variety of applications within optics and fibre communication systems. Optical isolators are used in a wide variety of applications within fibre communication systems. In advanced optical communication systems, optical circulators are used for bi-directional transmissions, wavelength division multiplexing networks, fibre amplifier systems, and optical time domain reflectrometers.
