The structured light field has specific spatial phase, spatial amplitude, and spatial polarization distribution. Through the nonlinear interaction between light and atoms, the light field information is encoded into the atomic medium, and the refractive index, polarization intensity, etc. of the atoms are spatially modulated to achieve dynamic control, mode conversion or precise measurement. It has broad application prospects in optical communication, quantum information, and optical imaging. Nonlinear frequency conversion provides a new way to control the frequency of laser, and under the drive of the spatial structured light field, it overcomes the limitation of the single dimension of traditional Gaussian beams, developing multiple artificially controllable degrees of freedom. The nonlinear control of the structured light field is one of the important research directions in nonlinear optics, making it possible to precisely control and analyze optical signals in all dimensions and all wavelengths, and strongly promoting the development of light field generation, transmission, manipulation and detection technologies. The laboratory has constructed a flexible and controllable nonlinear optical system based on rubidium atomic medium, and has achieved real-time optical information transmission, precise measurement of optical properties, and dynamic control of light field modes by using techniques such as four-wave mixing, self-phase modulation, cross-phase modulation, and polarization modulation. The current research contents include: (1) z-scan enhancement measurement technology based on Gaussian-Bessel beams; (2) orbital angular momentum identification method based on spatial self-phase modulation; (3) single-frame polarization-resolved spectroscopy based on vector beams; (4) research on nonlinear frequency conversion of perfect Poincaré beams; (5) research on nonlinear frequency conversion of spatially structured beams.
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1) Trans-spectral transfer of spatio-temporal optical Ferris wheel with nonlinear wave mixing, Photonics Research, 12, 2559 (2024).
2) High-Fidelity Frequency Converter in High-Dimensional Spaces, Laser & Photonics Reviews, 18, 2400368 (2024).
3) Sensitivity enhancement of nonlinear refractive index measurement by Gaussian-Bessel beam assisted z-scan method, Optics Express, 30, 7291-7298 (2022).
4) Identification of orbital angular momentum using atom-based spatial self-phase modulation, Optics Express, 31, 13528-13535 (2023).
5) Spatial mapping of the polarization-resolved spectrum based on vector-beam-assisted nondegenerate four-wave mixing, Optics Letters, 48, 303-306 (2023).
