Frequency stabilized lasers for coherent optical communications

We summarise some preliminary research and considerations on design of semiconductor frequency stabilized lasers for application in the coherent fiber optic communications as a reference laser. Semiconductor lasers applied to fiber optic communications have to meet several specific requirements such as narrow line width of the radiation, broad frequency range of the continuous tuning without mode hopping, capability to be stabilized upon natural references in a wide wavelength range up to 15 nm. The natural references can be found in the absorption bands of the different gases and vapors covering a wide spectral range around 1.5 μm