Thermo-optofluidics — On-chip light modulation as an application

In this paper thermo-optofluidics is introduced as a new subfield of microfluidics. The presented principle allows on-chip light modulation in a repeatable manner. Compared to other, previously reported thermo-optic devices the achievable maximum switching frequency can be more than doubled. On the design a liquid core/solid cladding waveguide is exposed to varying temperatures (ΔT of approx. 8.5°C). The temperature related changes of the refractive indices of core and cladding are of opposite directions resulting in a controllable on-off switching of light confinement within the waveguide. Besides on-chip light modulation, temperature sensing as well as various analysis setups can be realized using this novel principle.