| Abstract: | A thermal microring optical sensor is configured such that a portion of
the optical resonator and its associated waveguide are encased within a
cladding structure to minimize scattering losses along the waveguide and
also provide improved evanescent coupling efficiency between the
waveguide and the resonator. Functioning as a thermal sensor, incoming
radiation modifies the temperature of the resonator, which changes its
resonant frequency and, as a result, the percentage of light that it
evanescently couples from the waveguide. The cladding structure also
functions as a mechanical support for the resonator disk, eliminating the
need for a pedestal to suspend the disk above the support substrate.
Thermally-induced buckling of the optical waveguide is also reduced by
encasing the susceptible portion of the waveguiding within the cladding
structure. |