FROG technique for the entangled soliton pulses identification

To use the entangled soliton pulses which can be produced via fission of the two-soliton breather in the optical fiber with periodically varying along the fiber dispersion in different applications such as quantum communications and quantum sensing the determination of entanglement between the pulses are necessary. The generated pulses are shifted symmetrically in carrier frequency to the red and to the blue according to the breather pulse. We propose to use the frequency resolved gating technique (FROG), when the signal pulse and reference pulses are combined at the nonlinear crystal for frequency sum generation. varying the delay of the pulses the spectrogram can be measured. The signal at the zero frequency corresponds to the signal and reference pulse interference. The FROG technique allows to measure the amplitude and the phase of the signal pulse.