Fig. 2: Optical far-field characterization of dielectric bowtie cavities.

a Broadband spectrum of a cavity with δ = − 6 nm. The cavity mode interferes with a background mode yielding a Fano resonance centered at λ ~ 1520 nm, highlighted by the red box. b–d Spectra for six nominally identical devices for each tuning δ = { − 2, − 4, − 6} nm. The spectrum of each copy is offset incrementally by 0.25 nW nm⁻¹ for clarity. The full spectrum for cavity 5 is shown in a. The red lines show fits to the Fano lineshape. e Mean and standard deviation of resonant wavelength λ₀ (blue, left) and quality factor Q (red, right) against δ, extracted from the fits in b–d.