Two-step lithography process for passive and active polymer structure combination based on host-guest systems

Energy efficiency is a major challenge for scalable integrated photonic technologies, especially in applications such as electro-optical modulators, frequency combs, and all-optical interconnects. Organic materials offer a promising route toward low-energy photonics due to their high nonlinear optical (NLO) efficiency, tunable properties, and cost-effective wet-coating fabrication. A critical step is integrating low-loss passive waveguides with active host-guest structures on the same chip. We present a two-step lithography process enabling such integration. The process begins with Cu alignment markers on SiO₂, followed by SU-8 passive waveguide fabrication and a second lithography step defining active SU-8/dye resonant elements. Devices consisting of edge couplers, waveguides, and ring resonators were fabricated and characterized for optical losses and Q-factors. This approach demonstrates a pathway toward fully organic, energy-efficient photonic components such as frequency combs and other all-optical devices.