Fabrication of ultra-high Q silica microdisk using chemo-mechanical polishing

Here we demonstrate that adding a chemo-mechanical polishing (CMP) procedure to conventional photolithography, silica microdisk with ultra-high quality factors ($>10^8$) can be fabricated. By comparing the intrinsic optical factor (Q) measured at 970~nm, observe due significantly reduced surface roughness, 1550~nm wavelength water molecule absorption cavity supersedes Rayleigh scattering as dominant for Q degradation.