Analysis of integrated optical device with microfluidic channel for sensing application

In this work, double ring resonator is analyzed with a microfluidic channel, the coupling of light is observed from the bus waveguide to ring waveguide and then to bus waveguide. The light couples inside the ring for some duration of time that is till the length required to circulate inside the ring. The design is simulated in the Lumerical mode solutions, the light source of 1550nm is allowed to pass through the input port of the top bus waveguide. And the same light will be coupled into the ring waveguide and then enters through the bottom bus waveguide at port 3. The designed double ring resonator is placed on a SiO2, the ring and the bus waveguide is of the material silicon. The light couples from the bus waveguide initially and then couples with the ring waveguide. In the double ring resonator structure, the effective refractive index 3.4254 is observed and its group index of 3.5226. The effective index and the group index is calculated at the mode 5, where the light coupling is observed at the two ring waveguide. Later by placing a micro fluidic channel on top of the double ring waveguide the effective refractive index was 3.4168 and its group index was 3.5328. From the length and the FSR, the effective index of 3.4168 and the group index of 3.5328 was calculated, which is desired for the bio sensing application. Hence it was observed an increase in the group index indicates that the proposed design will be useful in bio sensing application and it can be further fabricated for a point of care devices.