Simulation of an asymmetric hexagonal microcavity with high-ratio fluorescence and high-efficiency directional emission.

Ratiometric fluorescent sensors are widely used in biological sensing and immunoassays due to their high sensitivity detection of analytes. The high-ratio value of fluorescence can increase the sensitivity of the fluorescence sensor; in addition, the directional emission can improve the efficiency of light collection and improve the effective use of radiation power. In previous studies, low fluorescence ratios and low directional emission efficiency have restricted the application of ratio fluorescence sensors. Based on the above constraints, this paper proposes an asymmetric hexagonal microcavity structure. By destroying the complete rotational symmetry of the hexagon structure, it achieves high fluorescence ratios and high-efficiency directional emission in the far-field range in the near-infrared wavelength range, which is of significance for the development of high sensitivity fluorescence sensors.