Fig. 3. Mapping resonances in the deformed silicon microdisk.

a Top-view SEM image of the quadrupolar microdisk. Here R = 7 µm and ε = 0.08. The width of bus waveguide and the gap size are 462 nm and 80 nm, respectively. The scale bar is 10 µm. b Experimentally recorded transmission spectrum along the bus waveguide. c Mode spacings of four groups of high Q resonances. Orange dots show their analytical values in an ideal quadruple. d Experimentally mapped field distributions of mode I-IV. The scale bars are 4 µm. e and f the corresponding numerically calculated traveling wave mode patterns and their Husimi maps