SiO_2 platform at 652–660 nm with integrated in-plane coupling waveguides. Critical coupling to several radial modes is demonstrated using a rib-like structure with a thin Si_3N_4 layer at the air-substrate interface to improve the coupling.
High quality factor (Q ≈ 3.4×10^6) microdisk resonators are demonstrated in a Si_3N_4 on SiO_2 platform at 652–660 nm with integrated in-plane coupling waveguides. Critical coupling to several radial modes is demonstrated using a rib-like structure with a thin Si_3N_4 layer at the air-substrate interface to improve the coupling.