infrared Infrared (IR), sometimes called infrared light, is electromagnetic radiation (EMR) with wavelengths longer than those of visible light. It is therefore invisible to the human eye. IR is generally understood to encompass wavelengths from around ...

optical communications Optical communication, also known as optical telecommunication, is communication at a distance using light to carry information. It can be performed visually or by using electronic devices. The earliest basic forms of optical communication date b ...

, C-band refers to the

wavelength In physics, the wavelength is the spatial period of a periodic wave—the distance over which the wave's shape repeats. It is the distance between consecutive corresponding points of the same phase on the wave, such as two adjacent crests, tro ...

range 1530–1565 nm, which corresponds to the amplification range of erbium doped fiber amplifiers (

EDFA An optical amplifier is a device that amplifies an optical signal directly, without the need to first convert it to an electrical signal. An optical amplifier may be thought of as a laser without an optical cavity, or one in which feedback from ...

s). Optical Fiber Communications
article in rp-photonics

(accessed Nov. 11 2010) The C-band is located around the absorption minimum in

optical fiber An optical fiber, or optical fibre in Commonwealth English, is a flexible, transparent fiber made by drawing glass (silica) or plastic to a diameter slightly thicker than that of a human hair. Optical fibers are used most often as a means to ...

, where the loss reaches values as good as 0.2 dB/km, as well as an atmospheric transmission window (see figures). The C-band includes the 50 GHz-spaced

DWDM In fiber-optic communications, wavelength-division multiplexing (WDM) is a technology which multiplexes a number of optical carrier signals onto a single optical fiber by using different wavelengths (i.e., colors) of laser light. This techni ...

ITU The International Telecommunication Union is a specialized agency of the United Nations responsible for many matters related to information and communication technologies. It was established on 17 May 1865 as the International Telegraph Unio ...

channels 16 (1564.68 nm, 191.6 THz) to 59 (1530.33 nm, 195.9 THz).

References

Infrared Optical communications {{telecomm-stub