Wavelength Filters

The chapter reviews all relevant filters (to be) used in fibre optic communication and covers generic filter structures including fibre coupler filters and Mach-Zehnder interferometers, diffraction-, arrayed waveguide-, and fibre Bragg gratings, Fabry-Pérot interferometers, thin film- and microring filters, interleavers, and acousto-optic filters. The presentations include the underlying generic physical concepts, implementations as stand-alone filters or subcomponents of optoelectronic integrated circuits, and filter modules. Typical performance data are given in the wavelength and frequency domain, relevant phase properties are discussed as well, and attention is also given to system implications of the various device properties.