Fig. 1. Microwave cavity model diagrams. (a) Microwave cavity body; (b) end covers; (c) ensemble of microwave cavity

Fig. 2. Rectangular transition waveguide structure

Fig. 3. Simulation curves of central microwave magnetic intensities under different coupling hole sizes at cavity wall

Fig. 4. Simulated results of microwave cavity magnetic fields. (a) Distribution of magnetic field intensity in middle section; (b) distribution of magnetic field intensity in central axis profile

Fig. 5. Microwave cavity optical path diagrams. (a) Horizontal light path diagram; (b) axis direction light path diagram

Fig. 6. Influence of aperture for fluorescence detection on microwave magnetic field intensity on microwave cavity wall

Fig. 7. Photo of microwave cavity after assembly

Fig. 8. S11 parameter of microwave cavity measured by single waveguide

Fig. 9. Transmission parameters of four waveguides