title: High Gain Submicrometer Optical Amplifier at Near-Infrared Communication Band.
abstract: Nanoscale near-infrared optical amplification is important but remains a challenge to achieve. Here we report a unique design of silicon and erbium silicate core-shell nanowires for high gain submicrometer optical amplification in the near-infrared communication band. The high refraction index silicon core is used to tightly confine the optical field within the submicron structures, and the single crystalline erbium-ytterbium silicates shell is used as the highly efficient gain medium. Both theoretical and experimental results show that, by systematically tuning the core diameter and shell thickness, a large portion of the optical power can be selectively confined to the erbium silicate shell gain medium to enable a low loss waveguide and high gain optical amplifier. Experimental results further demonstrate that an optimized core-shell nanowire can exhibit an excellent net gain up to 31  dB mm(-1), which is more than 20 times larger than the previously reported best results on the micron-scale optical amplifiers.
authors.affiliation: Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, School of Physics and Electronic Science, and State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University Changsha, Hunan 410082, People's Republic of China.
authors.forename: Xiaoxia
authors.initials: X
authors.lastname: Wang
authors.affiliation: Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, School of Physics and Electronic Science, and State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University Changsha, Hunan 410082, People's Republic of China.
authors.forename: Xiujuan
authors.initials: X
authors.lastname: Zhuang
authors.affiliation: Department of Materials Science and Engineering, University of California, Los Angeles, California 90095, USA.
authors.forename: Sen
authors.initials: S
authors.lastname: Yang
authors.affiliation: Department of Materials Science and Engineering, University of California, Los Angeles, California 90095, USA.
authors.forename: Yu
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, School of Physics and Electronic Science, and State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University Changsha, Hunan 410082, People's Republic of China.
authors.forename: Qinglin
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, School of Physics and Electronic Science, and State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University Changsha, Hunan 410082, People's Republic of China.
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Zhu
authors.affiliation: Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, School of Physics and Electronic Science, and State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University Changsha, Hunan 410082, People's Republic of China.
authors.forename: Hong
authors.initials: H
authors.lastname: Zhou
authors.affiliation: Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, School of Physics and Electronic Science, and State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University Changsha, Hunan 410082, People's Republic of China.
authors.forename: Pengfei
authors.initials: P
authors.lastname: Guo
authors.affiliation: Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, School of Physics and Electronic Science, and State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University Changsha, Hunan 410082, People's Republic of China.
authors.forename: Junwu
authors.initials: J
authors.lastname: Liang
authors.affiliation: Department of Materials Science and Engineering, University of California, Los Angeles, California 90095, USA.
authors.forename: Yu
authors.initials: Y
authors.lastname: Huang
authors.affiliation: Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, School of Physics and Electronic Science, and State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University Changsha, Hunan 410082, People's Republic of China.
authors.forename: Anlian
authors.initials: A
authors.lastname: Pan
authors.affiliation: Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, USA.
authors.forename: Xiangfeng
authors.initials: X
authors.lastname: Duan