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3-way coherent polarization synthesis experimental results based on polarization control
In order to alleviate the impact of atmospheric turbulence on coherent optical communications, two major techniques are currently used, namely, "large aperture telescope + single aperture adaptive optics technology" and "phased array technology." Compared with the first technique, the phased array technology has the advantages of small size, low cost, and high reliability of the telescope. In a phased array-based spatial coherent optical communication system, the received light beam is divided into multiple beams by the receiving array. Therefore, it is important to efficiently synthesize a plurality of sub-beams carrying communication signals to one laser beam.
Coherent polarization synthesis schematic (a) open loop (b) phase control closed loop (c) polarization control closed loop. PBC is a fiber polarization combiner, PC is a fiber phase compensator, and DPC is a polarization controller
This work was supported by the National Natural Science Foundation of China, the Innovation Fund of the Chinese Academy of Sciences, and the "Light of the West."
(Original title: Optoelectronics Progress in Coherent Polarization Synthesis Based on Fiber Optic Devices)
[China Instrument Network Instrument Development] Recently, the Institute of Optoelectronics, Chinese Academy of Sciences Institute of Optoelectronics Key Laboratory of Li-yang, Li Xinyang, Hao Chao Group made new progress in the research of coherent polarization synthesis technology: a coherent polarization synthesis technology based on fiber optic devices, respectively, proposed Using phase control and polarization control methods to achieve efficient in-fiber coherent polarization synthesis. This technology is based on a fully polarization-maintaining fiber-optic device, eliminating the need to consider the effects of spatial errors. It has high system stability, reliability, and ease of integration with other fiber-optic devices. It has a great potential in phased-array space-based coherent optical communication systems. Value. The relevant results were published in the recent Applied Optics and IEEE Photonics Technology Letters by Yang Yan as the first author. To address this issue, the research group proposed a coherent polarization synthesis technique based on fiber optic devices. The two linearly polarized light beams whose polarization states are perpendicular to each other can be combined into a single beam using an optical fiber polarization combiner. Due to the phase difference of the input beam, the combined beam has an arbitrary polarization state (Fig. 1a). In order to control the combined beam as linearly polarized light for the next stage of synthesis or for the demodulation of communication signals, the research group proposed two methods of phase control (Fig. b) and polarization control (Fig. c), respectively. Theoretical analysis and experimental verification. The results show that both methods can achieve efficient coherent polarization synthesis, effectively synthesize multi-beam linearly polarized light into a polarization-maintaining fiber, and output linearly polarized light.