Tightening and extending the grid for DWDM sources

We address the issue of stabilizing both fixed and tunable DWDM sources on grids spaced by less than 100 GHz, over a greater than 18 THz frequency range. We will discuss techniques that are compact, robust and cost-effective for actual transmitter cards. Fixed-frequency sources, generally DFBs, are the workhorse of existing DWDM systems.