Direction-Adjustable Single-Mode Lasing via Self-Assembly 3D-Curved Microcavities for Gas Sensing

Area of Science:

• Physics
• Materials Science
• Chemistry

Background:

• Drop-based microcavity lasers are valuable for physics and chemical detection due to low cost, high luminescence, and sensing capabilities.
• Achieving directional emission and high quality (Q) factors with traditional droplet self-assembly on planar substrates is challenging.

Purpose of the Study:

• To propose a single-mode microcavity laser with directional far-field emission using 3D-curved microcavities via droplet self-assembly.
• To realize acetic acid (AcOH) gas sensing using these novel microcavities.

Main Methods:

• Constructed trichromatic single-mode lasing in 3D-curved microcavities on silica fibers using organic polymer droplets and self-assembly.
• Regulated substrate curvature to achieve mode selection and directional lasing.
• Utilized the responsive nature of liquid organic polymers for gas sensing.

Main Results:

• Achieved single-mode lasing with directional far-field emission in anisotropic 3D-curved microcavities.
• Measured a high Q-factor of approximately 20,000.
• Demonstrated a single-mode laser sensor for AcOH gas with a short response time due to chemical reactions.

Conclusions:

• The study presents a novel approach for creating tuneable, directional microcavity lasers and chemical sensors.
• These findings advance quasi-3D-anisotropic whispering-gallery-mode microcavities for lab-in-a-droplet technologies.
• The developed microcavity lasers show potential for enhanced performance in both tuneable lasing and chemical gas sensing applications.