Eu3＋, Pr3＋, or Gd3＋ codoped Ce：YAG single crystals were grown by using the Czochralski method. The pho- toluminescence （PL） emission and excitation spectra and transmittance were measured and investigated. The a...Eu3＋, Pr3＋, or Gd3＋ codoped Ce：YAG single crystals were grown by using the Czochralski method. The pho- toluminescence （PL） emission and excitation spectra and transmittance were measured and investigated. The additional red-emitting bands were observed in the PL emission spectra of Eu,Ce：YAG and Pr, Ce：YAG single crystals and the forma- tion of noticeable peaks was studied with reference to the schematic energy level diagrams. A red-shifted phenomenon was observed in the PL emission spectrum of Gd,Ce：YAG. With codoped Eu3＋, Pr3＋, or Gd3＋ ions, warmer white light was achieved for the white light emitting diodes and the color rendering index became higher.展开更多
In this work, a heavily Er-doped fiber with an 8 μm core diameter and a numerical aperture of 0.13 was prepared by the modified chemical vapor deposition(MCVD) technique combined with the sol-gel method. The backgrou...In this work, a heavily Er-doped fiber with an 8 μm core diameter and a numerical aperture of 0.13 was prepared by the modified chemical vapor deposition(MCVD) technique combined with the sol-gel method. The background loss and absorption coefficient at 1530 nm were measured to be 20 d B/km and 128 d B/m, respectively. Thanks to the sol-gel method, the fiber showed a good doping homogeneity, which was confirmed through unsaturable absorption measurement. The net gains of three 25, 45, and 75-cm-long fibers were measured in the range of 1520 to 1600 nm, and the highest gain reached above 23 d B at both 1530 and 1560 nm in 25 and 75-cm-long fibers, respectively. The short-cavity laser performance was measured using centimeter-scale fibers. The maximum output power of 12 m W was demonstrated in a 6.5-cm-long active fiber with a slope efficiency of 20.4%. Overall, the prepared heavily Er-doped silica fiber is a promising item to be applied in a high-repetition-rate or single-frequency fiber laser.展开更多
Induced loss at 633 nm is tested in Yb3＋∕Al3＋co-doped silica fiber by a core pumped with a 974 nm laser and probed with a 633 nm laser. The fiber is prepared by the modified chemical vapor deposition method combine...Induced loss at 633 nm is tested in Yb3＋∕Al3＋co-doped silica fiber by a core pumped with a 974 nm laser and probed with a 633 nm laser. The fiber is prepared by the modified chemical vapor deposition method combined with solution doping. Different power scales of pump light and probe light are used in the tests. It is found that there is a dynamic equilibrium between photobleaching induced by 633 nm probe light and photodarkening（PD）induced by 974 nm pump light. For the first time to our knowledge, the effect of 633 nm probe laser power on an induced loss test of Yb3＋∕Al3＋co-doped silica fiber is studied quantitatively. It suggests that as long as the633 nm probe light power is less than 0.2 m W, the induced loss is mainly contributed by the PD effect of pumping light, and the deviation of induced loss is less than 5%.展开更多
Using a heavily erbium-doped aluminosilicate fiber prepared by the sol-gel method combined with high temperature sintering, the temperature dependence of the spectrum around the 1.55 nm band and single-mode fiber lase...Using a heavily erbium-doped aluminosilicate fiber prepared by the sol-gel method combined with high temperature sintering, the temperature dependence of the spectrum around the 1.55 nm band and single-mode fiber laser properties were investigated, respectively. The absorption cross section increases 29.2% at ~1558 nm with the temperature increasing from 20℃ to 140℃, while the emission cross section slightly increases4.3%. In addition, the laser slope of the heavily erbium-doped aluminosilicate fiber at 1558 nm decreases4.4% from 10.8% to 6.4% with the temperature increasing from 18℃ to 440℃. Meanwhile, an experiment lasting3 h proves that the fiber laser has excellent stability below 440℃.展开更多
文摘Eu3＋, Pr3＋, or Gd3＋ codoped Ce：YAG single crystals were grown by using the Czochralski method. The pho- toluminescence （PL） emission and excitation spectra and transmittance were measured and investigated. The additional red-emitting bands were observed in the PL emission spectra of Eu,Ce：YAG and Pr, Ce：YAG single crystals and the forma- tion of noticeable peaks was studied with reference to the schematic energy level diagrams. A red-shifted phenomenon was observed in the PL emission spectrum of Gd,Ce：YAG. With codoped Eu3＋, Pr3＋, or Gd3＋ ions, warmer white light was achieved for the white light emitting diodes and the color rendering index became higher.
基金This work was supported by the National Key R&D Program of China(No.2020YFB1805900)National Natural Science Foundation of China(NSFC)(No.62005297)+1 种基金Shanghai Sailing Program(No.20YF1455300)Shanghai Science International Cooperation Project(No.18590712900).
文摘In this work, a heavily Er-doped fiber with an 8 μm core diameter and a numerical aperture of 0.13 was prepared by the modified chemical vapor deposition(MCVD) technique combined with the sol-gel method. The background loss and absorption coefficient at 1530 nm were measured to be 20 d B/km and 128 d B/m, respectively. Thanks to the sol-gel method, the fiber showed a good doping homogeneity, which was confirmed through unsaturable absorption measurement. The net gains of three 25, 45, and 75-cm-long fibers were measured in the range of 1520 to 1600 nm, and the highest gain reached above 23 d B at both 1530 and 1560 nm in 25 and 75-cm-long fibers, respectively. The short-cavity laser performance was measured using centimeter-scale fibers. The maximum output power of 12 m W was demonstrated in a 6.5-cm-long active fiber with a slope efficiency of 20.4%. Overall, the prepared heavily Er-doped silica fiber is a promising item to be applied in a high-repetition-rate or single-frequency fiber laser.
基金supported by the Young Scientists Fund of the National Natural Science Foundation of China(No.61405215)the Youth Innovation Promotion Associationthe Special Program for Advanced Electronic Materials of the Ministry of Science and Technology,China(No.2016YFB0402201)
文摘Induced loss at 633 nm is tested in Yb3＋∕Al3＋co-doped silica fiber by a core pumped with a 974 nm laser and probed with a 633 nm laser. The fiber is prepared by the modified chemical vapor deposition method combined with solution doping. Different power scales of pump light and probe light are used in the tests. It is found that there is a dynamic equilibrium between photobleaching induced by 633 nm probe light and photodarkening（PD）induced by 974 nm pump light. For the first time to our knowledge, the effect of 633 nm probe laser power on an induced loss test of Yb3＋∕Al3＋co-doped silica fiber is studied quantitatively. It suggests that as long as the633 nm probe light power is less than 0.2 m W, the induced loss is mainly contributed by the PD effect of pumping light, and the deviation of induced loss is less than 5%.
基金financially supported by the National Natural Science Foundation of China(NSFC)(No.61775224)
文摘Using a heavily erbium-doped aluminosilicate fiber prepared by the sol-gel method combined with high temperature sintering, the temperature dependence of the spectrum around the 1.55 nm band and single-mode fiber laser properties were investigated, respectively. The absorption cross section increases 29.2% at ~1558 nm with the temperature increasing from 20℃ to 140℃, while the emission cross section slightly increases4.3%. In addition, the laser slope of the heavily erbium-doped aluminosilicate fiber at 1558 nm decreases4.4% from 10.8% to 6.4% with the temperature increasing from 18℃ to 440℃. Meanwhile, an experiment lasting3 h proves that the fiber laser has excellent stability below 440℃.
