Patent ID: 7903906

Claim:
An optical sensing system comprising: a light source; one or more bus waveguides comprising a first bus waveguide, the first bus waveguide comprising an input port that is in optical communication with the light source; and a microresonator configured so that the light source excites at least first and second resonant guided optical modes of the microresonator, the microresonator comprising: a first location on a surface of a core of the microresonator where a field intensity of the first mode is greater than a field intensity of the second mode, the microresonator core having a first cladding at the first location; a second location on a surface of the core of the microresonator where a field intensity of the first mode is less than or equal to a field intensity of the second mode, the microresonator core having a second cladding at the second location, the first cladding being different than the second cladding, wherein one of the first and second cladding is an optically-thick cladding layer, wherein a perturbation introduced at the optically-thick cladding layer will be unlikely to interact with a first or second mode of the microresonator.