Rayleigh scattering, mode coupling, and optical loss in silicon microdisks

Matthew Borselli, Kartik Srinivasan, Paul E. Barclay, Oskar Painter
2004 Applied Physics Letters  
High refractive index contrast optical microdisk resonators fabricated from silicon-on-insulator wafers are studied using an external silica fiber taper waveguide as a wafer-scale optical probe. Measurements performed in the 1500 nm wavelength band show that these silicon microdisks can support whispering-gallery modes with quality factors as high as 5.2 x 10^5, limited by Rayleigh scattering from fabrication induced surface roughness. Microdisks with radii as small as 2.5 microns are studied,
more » ... crons are studied, with measured quality factors as high as 4.7 x 10^5 for an optical mode volume of 5.3 cubic wavelengths in the material.
doi:10.1063/1.1811378 fatcat:75wz5yfe5ngfxmd2q2dwr3fcra