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Orbital angular momentum (OAM) spectrum correction in free space optical communication
Yi-Dong Liu1, Chunqing Gao, Xiaoqing Qi
1Department of Opto-electric Engineering, School of Information Science and Technology, Beijing Institute of Technology, Beijing 100081, China.
Optics Express
|June 12, 2008
Summary
This study introduces a method to correct orbital angular momentum (OAM) distortions in laser beams caused by pointing instability. Using the mean square value of OAM, the beam axis can be determined, recovering the initial OAM spectrum.
Area of Science:
- Optics and Photonics
- Free Space Optical Communication
Background:
- Orbital angular momentum (OAM) in laser beams offers potential for free space optical communication.
- OAM is highly sensitive to pointing instabilities like beam shift and tilt, which distort the OAM spectrum.
Purpose of the Study:
- To propose and demonstrate a method for correcting distorted OAM spectra in laser beams.
- To utilize the mean square value of OAM as an indicator for beam axis determination and spectrum recovery.
Main Methods:
- Qualitative analysis of the proposed method.
- Numerical simulations to demonstrate the effectiveness of the mean square value indicator.
Main Results:
- The mean square value of OAM effectively indicates the beam axis of superimposed helical beams.
- The proposed method successfully recovers the initial OAM spectrum from distortions.
Conclusions:
- The mean square value of OAM is a viable metric for correcting pointing instability-induced distortions.
- This method enhances the robustness of OAM-based free space optical communication systems.
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