Optical Communication Bands

Band	Descriptor	Wavelength (nm)
O Band	Original	1260 - 1360
E Band	Extended	1360 - 1460
S Band	Short Wavelength	1460 - 1530
C Band	Conventional	1530 - 1565
L Band	Long Wavelength	1565 - 1625
U Band	Ultralong Wavelength	1625 - 1675

From http://www.hardwaresecrets.com/article/154