Temporal SU(1,1) Interferometer Based on Four- Wave Mixing Time Lens and Its Applications in Ultrafast Time-Frequency Manipulation

Temporal optics, which enables lossless manipulation of ultrafast pulses, offers a new dimension for the regulation of quantum optical fields. In this paper, we established a temporal Fourier transform (TF) system based on a four-wave mixing (FWM) time lens and constructed a full quantum theoretical model for the resulting temporal SU(1,1) interferometer. This interferometer has high temporal resolution, can impose interference in both time and frequency domains, and is sensitive to the phase derivative. By introducing linear time-varying phase modulation, we achieved sub-picosecond precision in temporal autocorrelation measurements and generated ​an optical frequency comb with a fixed interval based on a feedback iteration mechanism. Theoretical analysis reveals ​the crucial regulatory role of time-frequency coupling in quantum interference, providing novel solutions for ultrafast quantum imaging, temporal mode encoding, and the generation of optical frequency quantization.