I am using Dual parallel mach zehnder modulator for generating initial seed comb lines. Using 50/50 coupler at output of DPMZM one arm of coupler is fed into low pi phase modulator. Using EDFA after PM and PC for controlling the state of polarization,optical splitter is used after PC and 90% power is feedback into other arm of coupler located at output of DPMZM and 10% to Optical spectrum analyzer. Using 10GHz modulating frequency. I can see abundant comb lines but those are highly unstable.How can I achieve stability and flatness of those comb lines? How can I optimize feedback loop for the desired purpose?
Thank you!!
Actually, at beginning, we also meet the problems you have (See the first comb generation paper we published_ An Experiment for Generating the 14-Tone Stable Carriers Using Recirculating Frequency Shifter). The generated comb lines are unstable and not flat. There are many issues you must notice: for example the quality of the modulator, RF signal applied, the gain of the EDFA, the quality of the filter, etc. The paper attached may solve you problems (High-quality frequency-locked optical frequency comb source for terabits optical communication system).
- Badges
- Science topic
- Similar topics
- Mathematical Sciences
- Graphs