A Broadband Infrared DFG Optical Comb Using All-PM Nonlinear Pulse Fiber Amplification Technique

A scheme of infrared comb based on fiber differential frequency generation (DFG) is proposed and demonstrated. The full polarization maintaining nonlinear pulse optical fiber amplification technology is adopted to generate nearly transform limited bicolor fundamental frequency pulses, so as to stably realize accurate time synchronization of broadband spectrum between fundamental frequency pulses. The 3dB bandwidth of DFG comb is 9 μ 2.05 near m μ m。 DFG combs can range from 7 to 10.5 μ The bandwidth of any tuning position is close to the theoretical limit. In addition, we show that it is necessary to suppress the number of chirps of fundamental pump pulses and reduce the number of fundamental signal pulses with limited transformation for achieving broadband and efficient DFG combs.