Tuneable microlasers that span the full visible spectrum, particularly red, green, and blue (RGB) colors, are of crucial importance for various optical devices. However, RGB microlasers usually operate in multimode because the mode selection strategy cannot be applied to the entire visible spectrum simultaneously, which has severely restricted their applications in on-chip optical processing and communication. Here, an approach for the generation of tuneable multicolor single-mode lasers in heterogeneously coupled microresonators composed of distinct spherical microcavities is proposed. With each microcavity serving as both a whispering-gallery-mode (WGM) resonator and a modulator for the other microcavities, a single-mode laser has been achieved. The colors of the single-mode lasers can be freely designed by changing the optical gain in coupled cavities owing to the flexibility of the organic materials. Benefiting from the excellent compatibility, distinct color-emissive microspheres can be integrated to form a heterogeneously coupled system, where tuneable RGB single-mode lasing is realized owing to the capability for optical coupling between multiple resonators. Our findings provide a comprehensive understanding of the lasing modulation that might lead to innovation in structure designs for photonic integration.

跨越整个可见光谱，特别是红、绿、蓝 (RGB) 颜色的可调谐微型激光器对于各种光学设备至关重要。然而，RGB微型激光器通常以多模工作，因为模式选择策略不能同时应用于整个可见光谱，这严重限制了它们在片上光学处理和通信中的应用。在这里，提出了一种在由不同球形微腔组成的异质耦合微谐振器中产生可调谐多色单模激光器的方法。每个微腔既充当回音壁模式 (WGM) 谐振器，又充当其他微腔的调制器，从而实现了单模激光器。由于有机材料的灵活性，可以通过改变耦合腔中的光学增益来自由设计单模激光器的颜色。得益于出色的兼容性，不同的颜色发射微球可以集成形成异质耦合系统，其中由于多个谐振器之间的光耦合能力，实现了可调谐的 RGB 单模激光。我们的研究结果提供了对激光调制的全面理解，这可能会导致光子集成结构设计的创新。