Impact of Tamm plasmon structures on fluorescence and optical nonlinearity of graphene quantum dots

Graphene Quantum Dots (GQDs) are crucial in biomedicine for sensitive biosensing and high-resolution bioimaging and in photonics for their nonlinear optical properties. Integrating GQDs with photonic structures enhances optical properties by optimizing light-matter interactions and enabling precise control over their emission wavelengths. In this work, we explore a facile synthesis method for GQDs by pulsed laser irradiation in chlorobenzene and highlight the transformative potential of Tamm Plasmon Cavity (TPC) structures for tuning and amplifying the photoluminescence and nonlinear optical properties of GQDs. The characterization of GQDs revealed their exceptional properties, including efficient optical limiting and stable photoluminescence. The study demonstrated that the TPC structure significantly amplifies nonlinear optical effects due to the high light-matter interaction, indicating the potential for advanced optical systems, including optical limiters and nonlinear optical devices. Furthermore, introducing GQDs into the TPC structure leads to a significant enhancement and tuning of fluorescence emission. The Purcell effect, in combination with the confined electromagnetic fields within the TPC, increases the spontaneous emission rate of GQDs and subsequently enhances the fluorescence intensity. This enhanced and tunable fluorescence has exciting implications for high-sensitivity applications such as biosensing and single-molecule detection.