Microstructured Organic Cavities with High‐Reflective Flat Reflectors Fabricated by Using a Nanoimprint‐Bonding Process

The integration of photonic microstructure into organic microcavities represents an effective strategy for manipulating eigenstates of cavity or polariton modes. However, well‐established fabrication processes for microstructured organic microcavities are still lacking. This study proposes a nanoimprint‐bonding process as a novel fabrication method for microstructured organic microcavities. This process relies on a UV nanoimprint technique utilizing two different photopolymer resins, enabling the independent fabrication of highly reflective reflectors and photonic microstructures without compromising the accuracy of each. The resulting organic microcavities demonstrate spatially localized photonic modes within dot structures and their nonlinear responses on the pumping fluence. Furthermore, a highly precise photonic band is confirmed within a honeycomb lattice structure, which is owing to the high quality factor of the cavity achievable with the nanoimprint‐bonding process. Additionally, a topological edge state is also observable within a zigzag lattice structure. These results highlight the significant potential of the fabrication method for advancing organic‐based photonic devices, including lasers and polariton devices. A feasible route of fabricating organic microcavity with photonic microstructure is proposed using nanoimprint lithography. By utilizing pre‐fabricated distributed Bragg reflectors and two kinds of photopolymerized resin, precise microfabrication and successful implementation of highly reflective mirrors are achieved simultaneously. This study highlights the great significance of the method for advancing organic‐based lasers and polariton devices.