Efficient Lasing Enabled by Enhanced Light-Matter Interaction through Aligned Nanoplatelets in Resonators

Colloidal quantum dots (CQDs) are promising optical gain media distinguished by their narrow emission spectra and adaptable wavelengths. However, their isotropic nature often results in randomly oriented transition dipoles within laser cavities, thereby reducing their coupling with the optical modes. Here, we propose nanoplatelets (NPLs) as an alternative. By aligning them on a large scale, we ensure well-oriented transition dipoles with the longitudinal modes of Fabry–Perot (F-P) cavities. This alignment enhances coupling with cavity modes, resulting in directional emission and a significant reduction in lasing thresholds by a factor of 2.19. Our approach illuminates pathways for optimizing CQD-based optoelectronic devices by improving light-matter interaction.