Wavelength control for fiber-grating lasers enables low-cost DWDM operation down to 25GHz channel spacing

摘要

We present a new, very cost-efficient control scheme to stabilise the mode and the emitted wavelength of Fibre-Grating Lasers. It permits to maintain the wavelength constant within +/- 5 pm while the output power may vary between -4 and +4 dBm. Such wavelength stability is a key requirement for dense wavelength-division multiplex (DWDM) systems, and we demonstrate its suitability down to 25 GHz channel spacings. The control scheme is based solely on the power at the laser's back facet, that is monitored with a photodiode. Therefore, this control scheme drastically reduces the complexity and cost of DWDM laser sources.