optical regenerator (rus. оптический регенератор) — a component of an optical communication system that regenerates digital optical signals.

Description

In long-distance communication systems, wave distortion and relative time delay deviation (lack of synchronisation) are accumulated even when optical amplifiers that regenerate signal amplitude are used. This is why periodic regeneration is usually required to regenerate the original waveform and synchronisation of signals. Complete (3R) regeneration includes three regenerating operations with a signal: regeneration of amplitude (amplification), regeneration of signal waveform and regeneration of synchronisation (see fig.).

In modern communication systems, these three operations are completed by an opto-electro-optical (OEO) converter. Such optical regenerators are called optical repeaters.

Optical repeaters detect optical signals, convert them into electric signals, completely regenerate the signal in its electric waveform and transmit it in the form of an optical signal. Optical repeaters are quite complex and expensive systems, as they are comprised of an optical receiver, electric regenerator and a transmitter.

To reduce the cost of OEO regenerators, a large number of optical repeaters are linked in a single photon integrated circuit also containing an optical multiplexer, demultiplexer and electronic channel switches [2].

Future long-distance communication systems are expected to be built with completely optical regenerators that will use non-linear optics methods to regenerate signal parameters without converting it into an electrical signal. Several methods of complete optical regeneration of signals have been proposed that are based on the phase self-modulation of signals in optical fibres or channel waveguides, phase cross-modulation, four-wave mixing and nonlinear saturation.

Illustrations

Amplification and regeneration of optical pulses.

Amplification and regeneration of optical pulses.


Authors

  • Nanii Oleg E.
  • Pavlova Elena G.

Sources

  1. Nanijj O. E. Fundamentals of digital fiber-optic communication systems (in Russian) // Lightwave Russian Edition. 2003. №1. P. 48–52.
  2. Mell S. "Digital Optical Networks" provide a simple, fast and flexible service delivery (in Russian) // Lightwave Russian Edition. 2005. №3. P. 19–20.

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