- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Phase Alignment With Minimum Complexity for Equal Gain Combining in Multi-Aperture Free-Space Digital Coherent Optical Communication Receivers
摘要： Digital coherent combining (DCC) technique can increase the free space optical signal collection area by combining the signals received by an array of small apertures in a coherent manner. To realize DCC the different versions of signals must be aligned in phase by the digital phase alignment algorithm (PAA). Low computation complexity is imperative for the PAA because the main obstacle to implement the PAA and DCC in a real-time manner is the availability of digital signal processing (DSP) circuits offering very high gate density and processing speed. In this paper we investigate the relationship between the computation complexity, optical phase offset estimation error and the combining loss for the equal gain combining technique. Analytical expressions are deduced allowing easy minimization of the computation complexity at an arbitrary input OSNR and acceptable combining loss. Extensive numerical simulations are carried out to validate the analytical expressions.
关键词： Multi-aperture free-space optical communication receivers,combining loss,minimum complexity,phase estimation error,phase alignment,digital coherent combining
更新于2025-09-19 17:13:59
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Multi-aperture fiber coherent combining system in urban horizontal atmospheric laser link
摘要： Multi-aperture receiver with optical combining architecture is an effective approach to overcome the turbulent atmosphere effect on the performance of the free-space optical (FSO) communications. In this paper, we built a 1 km urban horizontal link, and adopted beam combining system with four apertures at receiver. By analogy with aperture smoothing factor, we proposed the concept of fluctuation suppression ratio to evaluate the mitigation ability of the system on atmospheric fading. The experimental results confirmed that the beam combining system can perform best when the aperture interval is larger than the coherent length, and the performance decreases with the increase of the coherent length. Moreover, we found that the change of phase differences between the input beams is more than 40 ??rad, which provides reference for future system design.
关键词： Scintillation index,Atmospheric turbulence,Multi-aperture,Optical coherent combining
更新于2025-09-19 17:13:59
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Formation of the Feedback Loop for Phase Control of a Fiber Laser Array
摘要： Methods for phasing radiation channels for the coherent combination of linearly polarized fields of narrowband fiber lasers are considered. High efficiency of operation of the internal feedback loop based on interference of peripheral sections of radiation (Gaussian beam tails) of the phased channels is shown. This method is easily implementable. It allows scaling the power of optical phased arrays and does not require heavy optical elements. Equations for calculation of the optical scheme for implementation of the feedback loop are presented along with the experimental results on coherent combination of three beams.
关键词： optical phased arrays,feedback loop,coherent combining,fiber laser
更新于2025-09-19 17:13:59