Selection of Emission Wavelength of Lasing via a Hybrid Microcavity

In the applications of optical communication and light-matter interaction manipulation, the capability of on-demand lasing output with programmable and continuous wavelength tunability over a broad spectral range under low threshold is key functionality. However, the ability to control multiwavelength lasing characteristics within a small mode volume with high reconfigurability remains challenging. The number of dyes and the emission wavelengths of existing materials always restrict the color gamut. In this Letter, we introduce a selection of emission wavelength laser by injecting Rhodamine 6G solution mixed with Au nanoparticles in the metal-cladded slab-capillary hybrid microcavity. A mechanism for tuning laser emission wavelengths is designed by manipulating the diameter of Au nanoparticles in Rhodamine 6G solution. Precision control of distinctive lasing wavelengths and a narrower peak are achieved, along with a stable lasing beam output from both ends of the capillary due to coherent superposition. Our findings offer possibilities for realizing a micro selection of emission wavelength laser from a single overall structure.