Chromaticity-tunable white random lasing based on a microfluidic channel.

Area of Science:

• Photonics and Optics
• Materials Science

Background:

• Controlling the color and chromaticity of random lasing is crucial for practical applications, especially as high-luminance, speckle-free imaging sources.
• Existing random laser technologies often face limitations in chromaticity tunability and integration for white light generation.

Purpose of the Study:

• To achieve white coherent random lasing with tunable chromaticity.
• To explore the use of gold-silver (Au-Ag) nanowires and dye resonance energy transfer for random laser fabrication.
• To investigate the potential of these tunable random lasers in high brightness illumination, biomedical imaging, and sensor applications.

Main Methods:

• Fabrication of red, green, and blue random lasers using Au-Ag nanowires as scatterers within a capillary microfluidic channel.
• Utilizing plasmonic resonance in Au-Ag nanowire nanogaps/nanotips and capillary wall feedback for low-threshold lasing.
• Designing a white random laser system by combining the three primary color lasers and tuning chromaticity via pump power density.

Main Results:

• Successfully demonstrated red, green, and blue coherent random lasing with low thresholds.
• Achieved white coherent random lasing with flexibly tunable chromaticity by adjusting pump power density.
• Observed anisotropic spectra in the white random laser due to inter-laser coupling, enabling generation of various chromaticities across the visible spectrum.

Conclusions:

• The developed system provides a novel method for generating tunable white coherent random lasing.
• The use of Au-Ag nanowires and resonance energy transfer offers an effective strategy for color control in random lasers.
• These findings lay the groundwork for advanced applications in illumination, biomedical imaging, and sensing.