High quality factor silicon nitride microdisk resonators for chip-scale visible sensing

Ultra-high-quality (Q≫4×10
⁶
) microdisk resonators are demonstrated in a Si
3
N
4
platform at 655nm with straight and curved in-plane coupling waveguides. Selective coupling to specific radial orders and polarizations is demonstrated by phase-matching. TM modes show higher sensitivity to environmental modifications for sensing.