1 Key Laboratory of Education Ministry on Luminescence and Optical Information Technology, National Physical Experiment Teaching Demonstration Center, Department of Physics, School of Science, Beijing Jiaotong University, Beijing 100044, China
2 School of Electronic and Information Engineering, Beijing Jiaotong University, Beijing 100044, China
3 Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China
4 State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China
Frontiers of Optoelectronics
2022, 15(1): s12200
Author Affiliations
Abstract
Wuhan National Laboratory for Optoelectronics (WNLO), Huazhong University of Science and Technology, Wuhan 430074, China
The radical suppression of the photodarkening effect and laser performance deterioration via loading were demonstrated in high-power Yb-doped fiber (YDF) amplifiers. The photodarkening loss at equilibrium was 114.4 dB/m at 702 nm in the pristine fiber, while it vanished in the -loaded fiber. To obtain a deeper understanding of the impact of photodarkening on laser properties, the evolution of the mode instability threshold and output power in fiber amplifiers was investigated. After pumping for 300 min, the mode instability threshold of the pristine fiber dropped from 770 to 612 W, and the periodic fluctuation of the output power became intense, finally reaching 100 W. To address the detrimental effects originating from photodarkening, loading was applied in contrast experiments. The output power remained stable, and no sign of mode instability was observed in the -loaded fiber. Moreover, the transmittance at 638 nm confirmed the absence of the photodarkening effect. The results pave the way for the further development of high-power fiber lasers.
Photonics Research
2020, 8(3): 03000288
Author Affiliations
Abstract
Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 2018002 Graduate University of Chinese Academy of Sciences, Beijing 1000493 State Key Laboratory of Silicon Materials, Zhejiang University, Hangzhou 310027
The femtosecond laser induced void array inside Al2O3 crystals was discussed. The void array was formed spontaneously under the irradiation of a single beam of infrared femtosecond laser which was focused at a fixed point inside the Al2O3 crystal sample. It was found that the regular voids only could be fabricated near the sample surface, which was different from the situation in CaF2 single crystal reported before. The possible mechanism of the phenomena was also discussed.
微米点阵 飞秒激光 氧化铝晶体 140.7090 Ultrafast lasers 320.7130 Ultrafast processes in condensed matter, including semiconductors Chinese Optics Letters
2008, 6(5): 388
Photon Craft Project. Shanghai Institute of Optics & Fine Mechanics. Chinese Academy of Sciences and Japan Science and Technology Corporation, Shanghai. 201800. P.R. China
