Athermalization of laser operation
Athermalization refers to operation of semiconductor lasers with its wavelength unchanged even as the temperature is changed. As the ambient temperature increases, the output wavelength of the laser redshifts, which is an issue for Dense Wavelength Division Multiplexing (DWDM) where the laser output must remain within a narrow channel of roughly 50GHz. The solution to this has been to employ a cooling system to stabilise the ambient temperature, however this requires a lot of energy to operate.
If we use a discontinuous tuning shown by the black lines, mode hops will occur. However, the athermalisation can now be maintained in the range 10 to 85 oC.
Athermal operation of multi-section slotted tunable lasers. Wallace, M.J.; O’Reilly Meehan, R.; Enright, R.; Bello, F.; McCloskey, D.; Barabadi, B.; Wang, E.N.; Donegan, J. F. 2017 Optics Express 25(13) 14414-1442.