Active integrated liquid crystal-ring resonator platform for a dynamic optical power routing application

Active and reconfigurable integrated optical devices are highly desirable in modern technologies to enhance the functionality as well as real-time control of these devices. Despite their real-time practical applications, most of such devices are still passive, including micro-ring resonators (MRR). Here, we propose a voltage-tunable MRR device based on titanium oxide (TiO2) waveguides patterned over a silicon dioxide (SiO2) substrate, incorporating a liquid crystal (LC) strip as a dynamic refractive index (RI) modulation element. The structure consists of a TiO2 RR coupled to input, bus, and output waveguides, with a nanoscale LC strip embedded in the coupling region enabling active tunability. By varying the applied voltage, the effective RI of the LC changes from ordinary index to extraordinary index, enabling controlled modulation of the optical output intensity at 870 nm. Simulation results show that the output intensity at both the bus and output ports is highly sensitive to the RI of the LC, allowing the device to function as a voltage-controlled optical switch. Spectral analysis across 840-980 nm reveals wavelength-selective behavior with peak performance in terms of average intensity plots near 870-910 nm. The high-index TiO2 ensures efficient light confinement, while the LC offers low-power, electro-optic reconfigurability. The proposed active device holds strong potential for use in integrated photonic circuits, optical logic units, optical switching and routing, and wavelength-division multiplexing (WDM) applications.