兼顾增益与折射率变化的低偏振量子点材料研究

Study on Balancing Gain and Refractive Index Change of Quantum Dot with Low Polarization Dependence

对比分析了InGaAs/InGaAsP柱状量子点材料TE模和TM模增益谱及其折射率变化谱随点区材料组分、垒区材料组分和量子点高宽比的变化特性,并剖析了其中的物理机理。进一步联合考虑点区和垒区组分变化对兼顾增益与折射率变化以及偏振相关性的影响,提出了一种多参数调配方法,并据此设计出在1550nm通信波段(1540~1560nm)内兼顾增益与折射率变化的低偏振量子点材料In0.97Ga0.03As/In0.76Ga0.24As0.52P0.48。最后通过分析,选定合适的工作载流子浓度。当载流子浓度为0.6×10^24 m^-3时,TE模和TM模的3dB谱宽交叠区面积分别为8.66×10^3和7.55×10^3nm/cm,增益和折射率变化的偏振相关性分别在3%和10%以内。研究结果有助于未来全光网络中关键器件的优化设计。

The spectrum characteristics of gain and refractive index change of TE mode and TM mode of InGaAs/InGaAsP columnar quantum dot versus dot material components,barrier material components and aspect ratio are contrastively analyzed,and the physical mechanism are dissected.The effects of changes of dot components and barrier components on balancing gain and refractive index change and polarization are further jointly investigated,then a multi-parameter adjustment method is proposed,and the In0.97Ga0.03As/In0.76Ga0.24As0.52P0.48 quantum dot with low-polarization that balances gain and refractive index change within 1550nm communication band(1540~1560nm)is designed.Finally,the appropriate carrier concentration is selected through analysis.When the carrier concentration is 0.6×10^24m^-3,the overlap region area of 3dB spectrum width of TE mode and TM mode is 8.66×10^3nm/cm and 7.55×10^3nm/cm respectively,and the polarization dependence of gain and refractive index change is smaller than 3% and 10%,respectively.The research result is helpful for the optimization design of some key devices in the future all-optical network.