Stable control of the fiber laser phased array under long-range turbulent atmosphere. (February 2022)

• Record Type: Journal Article
• Authors: Huang, Guan; Lv, Guoyun; Fan, Yangyu; Geng, Chao; Li, Xinyang
• Is Part Of: Optics & laser technology. Volume 146(2022)
• Publication Date: 2022-02
• Subjects: Fiber laser phased array -- Optimization algorithm -- Atmospheric turbulence -- Lock-in amplifier; Optics -- Periodicals; Lasers -- Periodicals; Electronic journals; 621.366
• DOI: 10.1016/j.optlastec.2021.107528
• Languages: English
• ISSNs: 0030-3992

Abstract

Highlights: The basic principle and the challenges of fiber laser phased array are introduced. The negative impacts of noise and light propagation delay are analyzed. Gradient estimator based on lock-in amplifier is designed to solve problems. Comparison experiments are conducted in the free space with a distance of 40 m. Abstract: Fiber laser phased array (FLPA) plays an important role in the laser projection applications, such as free-space optical communication and directed energy. However, the turbulence suppression effect of FLPA is severely limited in the long-range atmospheric environment. In this paper, the basic principle of FLPA is introduced, and the practical challenges are analyzed in detail. To improve the performance of FLPA, a gradient estimator based on the lock-in amplifier (LIA-ES) is introduced. Experiments based on two-channel FLPA were conducted in the free space with the beam's propagation distance of 40 m, and the results showed that when the LIA-ES was employed, the energy transfer efficiency of FLPA was improved by 2.22%, and the stability was improved by 25.9%. In addition, when an equivalent beam's propagation distance of 30 km was introduced, the LIA-ES can improve the energy transfer efficiency by 62.7%, and improve the stability by 75.9%.