Study on Properties of Microcavity Resonant Modes of GaN Based Hexagonal Photonic Crystals

This paper proposes a resonant microcavity structure with different size defect holes of GaN based hexagonal photonic crystal in the 440 nm blue band. The resonance and field distribution properties of the microcavity structure before and after the addition of different size holes in the central dielectric region of the photonic crystal were analyzed by simulation calculation. The correlation and operation mechanism between the microcavity structure and different structural parameters of the photonic crystal was studied, including the duty ratio of the periodic porosity region and the duty ratio of the central dielectric defect region. The influence of duty ratio on quality factor (<tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$Q$</tex>) and resonant wavelength of microcavity was discussed. The results show that the defect structure can be effectively formed by adding small size etching air holes in the central dielectric region of the photonic crystal, thus enhancing the localization properties of the field distribution modes of the microcavity. The relative intensity of the field distribution Mode2 is 45, and the quality factor <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$Q$</tex> is 3000. The research has theoretical significance for the design of GaN based blue band resonator with high performance.