氮化镓基异质结构光子晶体微腔特性研究

Study on the characteristics of Gallium Nitride based hetero-structure photonic crystal micro-cavity

本论文提出了氮化镓基有源体系的异质结构光子晶体谐振腔,以实现高品质因子和小模场体积的有源集成蓝光谐振。通过能带分析,明确了异质结构光子晶体谐振腔的工作机理。基于光子晶体的能带带边和带隙原理,实现了光子面内反馈、高品质因子谐振和面外垂直发射。基于时域有限差分方法,研究了核心区和包层区不同谐振腔参数下的谐振特性。讨论了微腔结构与谐振品质因子、腔损耗、谐振频率及模场体积等的影响关系。研究表明,通过异质结构可以有效地降低面内谐振损耗,实现了有源集成型蓝光波段的Purcell因子达到769,模场体积为0.7(λ/n)3。该研究为蓝光波段高Q/Vm谐振腔的设计开辟了道路,同时为具备优异谐振特性的异质结构光子晶体微腔的研究奠定了方法和理论基础。

This paper proposes a two-dimensional heterostructure photonic crystal on a GaN-based active platform for achieving a resonant microcavity in the blue band with a high quality(Q)factor and small mode volume(Vm). The working mechanism of the heterostructure photonic crystal resonator is explained through band structure analysis. Based on the band edge and band gap principles applicable to photonic crystals,photonic in-plane feedback,a high Q factor resonance,and out-of-plane vertical emission are realized. The resonance characteristics of the core and cladding regions using different cavity parameters are studied by finite difference time domain(FDTD)simulation. The relationships among the microcavity structure and the resonance Q factor,cavity loss,resonance frequency,and Vmare discussed. These findings pave the way for designing high-Q/Vmresonators in the blue band and establishing a method with a theoretical basis for studying heterostructure photonic crystal microcavities with excellent resonance characteristics.