Lasing from reduced dimensional perovskite microplatelets: Fabry-Pérot or whispering-gallery-mode?

Area of Science:

• Materials Science
• Optics
• Condensed Matter Physics

Background:

• Cesium lead bromide (CsPbBr3) perovskites are promising for green-color lasing devices due to their stability and high emission efficiency.
• Understanding cavity modes in CsPbBr3 microplatelets (MPs) is essential for optimizing laser performance but remains controversial.

Purpose of the Study:

• To explore and clarify the origins of cavity modes in CsPbBr3 MPs lasers.
• To investigate the transition between different lasing modes under varying conditions.

Main Methods:

• Utilized angle-resolved microphotoluminescence Fourier imaging technique.
• Analyzed CsPbBr3 microplatelets (MPs) with varying edge lengths (L).
• Investigated lasing modes at room temperature under different excitation densities.

Main Results:

• Verified a transition from in-plane Fabry-Pérot (F-P) mode lasing to whispering-gallery-mode (WGM) lasing at room temperature.
• Observed F-P lasing predominantly in larger MPs (L > 13 μm), suppressed by decreasing L or increasing excitation density.
• Confirmed WGM lasing as predominant in all MPs at high excitation densities.
• Classified the parity and symmetry of in-plane F-P modes.

Conclusions:

• The study advances the fundamental understanding of lasing modes in planar microcavities.
• Findings provide insights into the transition dynamics between F-P and WGM lasing in CsPbBr3 MPs.
• Results support the application of these materials in on-chip interconnection and quantum optics.