0.9-µm Nd-doped fiber amplifier seeded by a broadband semiconductor optical amplifier

The broadband fiber source features low coherence, high brightness, and high temporal stability, making it attractive for sensing, imaging, and communication. Although broadband fiber sources have achieved remarkable progress in many wavelength bands, high-power 0.9-µm broadband fiber sources, which are critically needed for applications including atmospheric sensing and blue-green light generation for deep-sea communication, remain scarce. In this paper, a 0.9-µm Nd-doped all-fiberized broadband fiber source is demonstrated. The broadband fiber source is based on a semiconductor optical amplifier as the seed and three stages of fiber amplifiers utilizing Nd-doped fiber as the gain medium. A maximum output power of 21.20 W is obtained at a central wavelength of 930 nm with a 3-dB linewidth of ∼ 10 nm. This source also exhibits good beam quality with M x 2 = 1.378 and M y 2 = 1.404 , as well as high temporal stability. To the best of our knowledge, this work represents the first demonstration of a ten-watt-level broadband fiber source in the 0.9-µm band, and such a high-power source holds great potential for atmospheric sensing and underwater applications.