Radiation-Hardened Erbium-Doped Fiber from Xi'an Institute of Optics and Precision Mechanics Completes On-Orbit Verification for Spaceborne Laser Communication

An aerospace-grade radiation-resistant erbium-doped fiber independently developed by the team of Hou Chaoqi and researcher Guo Haitao at the Laboratory of Photonic Functional Materials and Devices, Xi'an Institute of Optics and Precision Mechanics (XIOPM), Chinese Academy of Sciences, has completed one full year of continuous, stable and normal operation in orbit. This marks a major breakthrough for China in the domestic production of radiation-resistant erbium-doped fiber for space applications, representing a leap forward in self-reliance and independent control.

Today, the global satellite internet industry is entering a period of rapid growth. Internationally, low-Earth-orbit constellation programs represented by "Starlink" have completed large-scale deployments and achieved engineering validation of inter-satellite laser communications. In 2020, satellite internet was included by China's National Development and Reform Commission in the scope of "new infrastructure".

Erbium-doped fiber is the core gain medium for optical amplifiers at the signal receiving and transmitting ends of laser communication systems. In space, high-energy particle irradiation creates radiation-induced color centers inside the fiber, sharply increasing fiber loss and severely degrading laser gain performance, or even causing failure. This has become a key factor limiting the performance, lifetime and reliability of spaceborne laser communication systems. Previously, China's space-grade erbium-doped fiber relied on imports for a long time.

Figure: Space-grade radiation-resistant erbium-doped fiber independently developed by the team

In response, a research team led by Researcher Hou Chaoqi, Researcher Guo Haitao, Associate Researcher She Shengfei, and Special Research Assistant Wang Gencheng has revealed the radiation damage effects and mechanisms of erbium-doped fibers under space high-energy ion irradiation, and proposed an innovative new fiber structure that suppresses the post-irradiation increase in temperature sensitivity. The team successively overcame key technologies including uniform dispersion of erbium ions in ultra-low co-dopant systems, radiation hardening through composition and pretreatment control, and the fabrication of high-efficiency radiation-resistant erbium-doped fiber, successfully developing a radiation-resistant erbium-doped fiber with independent intellectual property rights.

The fiber has a core numerical aperture of 0.22, background loss below 15 dB/km at 1200 nm, and laser efficiency of 34%. Under 100 krad(Si) irradiation, radiation-induced gain degradation is as low as 0.024 dB/krad(Si), with performance metrics reaching internationally advanced levels.

Figure: Photo of radiation-resistant erbium-doped fiber and laser performance test results

In 2025, a space-grade optical amplifier based on this fiber was successfully launched into orbit aboard a satellite. To date, the fiber, integrated in a laser communication terminal, has passed a series of key assessments, including hardware performance testing, coaxiality calibration, and maximum laser power output. All performance indicators are normal, and it has operated stably in orbit for a full year.

This achievement provides core material support for China's spaceborne laser communications and is of great significance to major missions such as the deployment of China's satellite internet constellations and deep space exploration.

This work was supported by the Key Deployment Research Program of the Chinese Academy of Sciences and the CAS Light of West China - West China Interdisciplinary Team project.

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