Hybrid Si-LiNbO₃ microring electro-optically tunable resonators for active photonic devices.

Hybrid Si-LiNbO₃ electro-optic tunable ring resonators have been proposed and demonstrated as a path to achieving ultracompact and high-speed electro-optic devices. Free standing single crystal LiNbO₃ microplatelets (~mm long and ~1 μm thick) were obtained from a z-cut LiNbO₃ substrate by ion implantation and thermal treatment. The platelets were transferred and thermally bonded on top of Si resonators that were fabricated in a Si-on-insulator platform by a 0.

Analysis and demonstration of coupling control in polymer microring resonators using photobleaching.

We describe postfabrication trimming of coupling in both laterally and vertically coupled polymer microring resonators (MRRs), using photobleaching. For both cases, a tapered directional-coupler-based simple analytical model is developed to simulate the change in coupling due to a bleaching-induced decrease in refractive index. A tightly focused laser beam spot (a few kilowatts per square centimeter) is used to precisely bleach the coupling region alone.

Optical resonant sensors: a method to reduce the effect of thermal drift.

The use of a whispering gallery mode (WGM) resonator with an ultrahigh quality factor Q is promising in highly sensitive, label-free, lab-on-a-chip sensor applications. We investigated a novel method of using the differential frequency of TE and TM modes to reduce the thermal noise baseline, which commonly limits the sensitivity of WGM sensors. We studied the temperature dependence of WGM based sensors and experimentally demonstrated the reduction of temperature fluctuation and thus a significant improvement in the practical sensor detection limit.

Microring-resonator-based sensor measuring both the concentration and temperature of a solution.

We propose and investigate experimentally a micro-ring-resonator-based sensor with which we can measure both the concentration and temperature of glucose solution. It consists of two micro-ring resonators consecutively coupled to a bus waveguide by the overlap between them. The resonance wavelengths of the two resonators change similarly with the temperature but differently with the concentration.