Optical phase cloning by an integrated dual-parallel Mach-Zehnder modulator

The use of a dual-parallel Mach-Zehnder modulator in a feed-forward configuration is shown to serve the purpose of cloning the optical phase of a master oscillator on a distributed-feed-back (DFB) slave laser exhibiting a multi-MHz-wide frequency noise spectrum. A residual phase error of 113 mrad is obtained together with an extremely high control bandwidth of hundreds of megahertz and a gigahertz-level capture and tuning range. Besides offering a dramatic improvement over feedback loops, this approach is susceptible of hybrid integration in a cost-effective compact device benefiting from the wide tunability of DFB lasers. (C) 2015 Optical Society of America