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

Abstract

Here, we demonstrate that adding a chemo-mechanical polishing procedure to conventional photolithography, a silica microdisk with ultra-high quality factors (>108) can be fabricated. By comparing the intrinsic optical quality factor (Q) measured at 1550, 970, and 635 nm wavelengths, we observe that due to the significantly reduced surface roughness and the hydrophilic nature of the disk surface, at 1550 nm wavelength, the water molecule absorption at the cavity surface supersedes Rayleigh scattering as the dominant factor for Q degradation.