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Spatially dependent Raman gain by vortex beam in a four-level N-typed atomic system
Tong Zhang1,2, Kai-Kai Zhang1,2, Xu Deng1,2
1School of Physics and Optoelectronic Engineering, Yangtze University, Jingzhou, 434023, Hubei, China.
Scientific Reports
|March 14, 2025
Summary
Researchers demonstrate controlling spatial Raman gain in cold atoms using Laguerre-Gaussian vortex beams. Adjusting topological charges and optical parameters enables manipulation of Raman gain spectra, leading to vortex-induced transparency and gain.
Area of Science:
- Atomic, Molecular and Optical Physics
- Quantum Optics
- Nonlinear Optics
Background:
- Spatial control of optical gain is crucial for advanced optical applications.
- Cold atomic ensembles offer unique platforms for manipulating light-matter interactions.
- Vortex beams, characterized by orbital angular momentum, provide novel ways to structure light.
Purpose of the Study:
- To propose and investigate an efficient scheme for controlling spatial Raman gain in a cold atomic ensemble.
- To explore the influence of Laguerre-Gaussian (LG) vortex beams on Raman gain.
- To demonstrate the manipulation of Raman gain profiles and induce novel optical phenomena.
Main Methods:
- Utilizing a four-level N-type cold atomic ensemble.
- Employing Laguerre-Gaussian (LG) vortex beams for driving and control fields.
- Analyzing the effects of topological charges (TCs) and optical parameters on Raman gain spectra.
- Investigating the conditions for vortex-induced transparency (VIT) and vortex-induced gain (VIG).
Main Results:
- Spatial Raman gain can be effectively controlled by adjusting optical parameters and topological charges of vortex beams.
- Demonstrated manipulation of the radial distribution of Raman gain spectra.
- Observed vortex-induced transparency (VIT) and vortex-induced gain (VIG) phenomena.
- Achieved controlled azimuthal modulation of Raman gain profiles using a combination of travelling-wave and vortex fields.
Conclusions:
- The proposed scheme offers an efficient method for controlling spatial Raman gain in cold atomic ensembles.
- The findings provide a feasible approach for generating novel vortex beams using cold atoms.
- This research opens possibilities for advanced optical beam shaping and manipulation.
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