Passive fiber components are becoming increasingly available in a variety of different types and forms to perform important signal processing and conditioning tasks not only in optical communication systems but also in sensors (see Ref. 1 for a comprehensive review of fiber devices). Devices capable of tunable optical filtering and wavelength-selective branching, for example, are essential elements in high-capacity wavelength-division-multiplexed transmission systems and multichannel optical fiber local area networks and find application in general signal processing/conditioning. They can be used for shot-noise control, channel selection, wavelength-selective optical channel routing, dispersion compensation, and frequency control (in feed-forward laser resonators). Fiber polarizers and compensators as well are an integral part of coherent lightwave communication systems, where typically they control the state of polarization of light ahead of polarization-sensitive components, such as the optical detector/mixer in a coherent optical communication receiver.
© 1988 Optical Society of AmericaPDF Article