Timing phase noise reduction of modelocked quantum‐dot lasers by time‐delayed optoelectronic feedback

A novel optoelectronic‐feedback stabilisation scheme for passively modelocked semiconductor lasers is demonstrated. By electrical modulation of the absorber section with a signal directly obtained from the time‐delayed optical laser output, a significant broadband reduction of timing phase noise (TPN) is achieved without the use of a reference oscillator. The similarity to TPN measurement results obtained by an all‐optical feedback configuration suggests that the presented optoelectronic and the all‐optical feedback configuration are based on a common underlying TPN reduction mechanism.