为实现2μm低发散角激光,提出在Ga Sb基半导体激光器中引入布拉格反射波导,利用光子带隙效应替代传统的全反射进行光场限制。研究了分布反馈反射镜(DBR)的厚度、对数、高低折射率DBR厚度比以及中心腔厚度等参数对激光器垂直远场发散角...为实现2μm低发散角激光,提出在Ga Sb基半导体激光器中引入布拉格反射波导,利用光子带隙效应替代传统的全反射进行光场限制。研究了分布反馈反射镜(DBR)的厚度、对数、高低折射率DBR厚度比以及中心腔厚度等参数对激光器垂直远场发散角和光限制因子的影响。结果表明:垂直远场发散角随单对DBR厚度的增加而减小;光限制因子与远场发散角都随拉格反射镜对数的增加而减小,随高低折射率DBR厚度比的减小而增大;随着中心层厚度的增大,光限制因子减小而远场发散角增大。最终在理论上优化设计出了一种双边布拉格反射波导结构的超低垂直发散角2μm Ga Sb基边发射半导体激光器,其垂直远场发散角可降低到10°以下。展开更多
An LD directly-pumped solid-state laser is considered to be one of the most promising mid-infrared light sources because of its simple principle,small size,and compact structure for the generation of mid-infrared(MIR)...An LD directly-pumped solid-state laser is considered to be one of the most promising mid-infrared light sources because of its simple principle,small size,and compact structure for the generation of mid-infrared(MIR)lasers in the 3-5µm band.However,the quantum defect of LD directly-pumped MIR solid-state lasers will be much larger than that of ordinary near-infrared LD pumped solid-state lasers,which may lead to thermal damage and limit their development.In order to solve this problem,the methods of reducing the specific surface area of the crystal and improving the thermal energy released by the crystal structure are discussed,and the opti⁃mal length of the laser crystal is determined.The cooling structures of barium yttrium fluoride laser crystals(Ho^(3+):BY_(2)F_(8))of different lengths were studied by thermal simulation using COMSOL software.The experimen⁃tal results show that the output power can be increased and the thermal stress in the laser crystal can be alleviated by using the laser crystal whose length is slightly shorter than that of the cooler.The final experiment shows that when the pump repetition rate is 15 Hz and the pulse width is 90µs,the single pulse energy is 7.28 mJ at the out⁃put wavelength of 3.9µm,which is about 3 times as large as that of the crystal with the length of 10 mm(2.81 mJ).Such results should be another breakthrough of our team since the first directly-pumped solid-state MIR laser was realized more than a year ago.It might pave the way for the construction of a feasible MIR laser in the near future.展开更多
文摘为实现2μm低发散角激光,提出在Ga Sb基半导体激光器中引入布拉格反射波导,利用光子带隙效应替代传统的全反射进行光场限制。研究了分布反馈反射镜(DBR)的厚度、对数、高低折射率DBR厚度比以及中心腔厚度等参数对激光器垂直远场发散角和光限制因子的影响。结果表明:垂直远场发散角随单对DBR厚度的增加而减小;光限制因子与远场发散角都随拉格反射镜对数的增加而减小,随高低折射率DBR厚度比的减小而增大;随着中心层厚度的增大,光限制因子减小而远场发散角增大。最终在理论上优化设计出了一种双边布拉格反射波导结构的超低垂直发散角2μm Ga Sb基边发射半导体激光器,其垂直远场发散角可降低到10°以下。
基金Supported by the National Key Research and Development Program of China(2021YFA0718803)。
文摘An LD directly-pumped solid-state laser is considered to be one of the most promising mid-infrared light sources because of its simple principle,small size,and compact structure for the generation of mid-infrared(MIR)lasers in the 3-5µm band.However,the quantum defect of LD directly-pumped MIR solid-state lasers will be much larger than that of ordinary near-infrared LD pumped solid-state lasers,which may lead to thermal damage and limit their development.In order to solve this problem,the methods of reducing the specific surface area of the crystal and improving the thermal energy released by the crystal structure are discussed,and the opti⁃mal length of the laser crystal is determined.The cooling structures of barium yttrium fluoride laser crystals(Ho^(3+):BY_(2)F_(8))of different lengths were studied by thermal simulation using COMSOL software.The experimen⁃tal results show that the output power can be increased and the thermal stress in the laser crystal can be alleviated by using the laser crystal whose length is slightly shorter than that of the cooler.The final experiment shows that when the pump repetition rate is 15 Hz and the pulse width is 90µs,the single pulse energy is 7.28 mJ at the out⁃put wavelength of 3.9µm,which is about 3 times as large as that of the crystal with the length of 10 mm(2.81 mJ).Such results should be another breakthrough of our team since the first directly-pumped solid-state MIR laser was realized more than a year ago.It might pave the way for the construction of a feasible MIR laser in the near future.
