Optical spectral bands

Telecommunication developed advanced technologies last 2-3 decades and offers more advancement in next a few decades. Optical fibers and communication using them are in extensive use now. Optic fiber communication offers more information transmission capacity, immunity to electrical interference, wide bandwidth, high degree of signal security, lack of cross-talk and enhanced safety. Optical region of electromagnetic spectrum ranges from 5 nm in the ultraviolet region to 1mm in the infrared region. Visible band comprises of wavelength 400 nm to 700 nm. Normally optical fiber communication system uses the near infrared spectral band with range 770 nm to 1675 nm. Since longer wavelength band 1260 nm to 1675 nm offers superlative performance, international telecommunication union (ITU) fixed 6 spectral bands that can be used for long distance communication. These bands are original band (O-band with 1260 nm to 1360 nm), Extended band (E-band with 1360 nm to 1460 nm), Short band (S-band with 1460 nm to 1530 nm), Conventional band (C-band with 1530 nm to 1565 nm), Long band (L-band with 1565 nm to 1625 nm) and Ultra long band (U-band with 1625 nm to 1675 nm).