L band (infrared)

Fibre-optic telecommunicaitons

Absorption in fiber in the range 900–1700 nm

In infrared optical communications, L-band refers to the wavelength range 1565–1625 nm.^[1] The L-band is located next to the conventional (C) band (1530–1565 nm).

Infrared astronomy

Atmospheric windows in the infrared. The L band is the transmission window centred on 3.5 micrometres

In infrared astronomy, the L band is an atmospheric transmission window centred on 3.5 micrometres (in the mid-infrared).