Research On Resonance Characteristics Of GaN-Based Heterostructure Photonic Crystal Microcavity

This research innovatively proposes a combination of Ga N-based active suspended thin film structure and heterostructure photonic crystal resonator to carry out research on the resonance characteristics in the blue light band.The heterostructure microcavity realizes the controllability of resonance characteristics such as resonance frequency,mode field volume and quality factor by changing the cavity structure parameters.Combined with the layer structure design of the suspended film,a low-loss resonance feature with a small mode field volume with high coupling strength of the active layer and the coupling strength of the photonic crystal layer can be realized.In this study,the finite-difference time domain method was used to optimize the etching depth,lattice constant and air hole radius parameters of the infinite-area photonic crystal according to the changing law of resonance wavelength and quality factor Q,and the out-of-plane loss was obtained.Then reduce the area of the photonic crystal to study the change of the resonance wavelength and Q value,and calculate the in-plane loss under a specific area.On this basis,the photonic crystal with a side length of 6μm is used as the core layer,the air hole radius and the number of periods of the cladding are designed and optimized according to the energy band structure relationship and the Q value,and then the above parameters are fixed,and the effect of different core areas on the Q value and resonance The effect of wavelength.By comparing the Q value,mode field volume and coupling strength under different parameters,the microcavity parameters with high Q/V_m are selected.Finally,the effect of lattice type on the properties of the microcavity is investigated.This design utilizes the energy band gap of the heterostructure to achieve low-loss in-plane feedback.The resonance wavelength is near 451 nm,the Q value is in the order of 10~4,and it has a small mode field volume and cavity size,and the Q/V_m reaches 10~4.The research is as follows:The design of the structural parameters of the high-Q/V_m microcavity in the blue light band provides a reference,and at the same time,it provides a strong design and theoretical guarantee for the fabrication and realization of a blue laser with high-speed modulation characteristics based on this microcavity.