Random lasing carbon dot fibers for multilevel anti-counterfeiting

Area of Science:

• Materials Science
• Optics and Photonics
• Nanotechnology

Background:

• Random lasers offer convenient cavity-free designs and find applications in various fields.
• Carbon dots (CDs) are promising nanomaterials with tunable optical properties.
• Developing robust materials for advanced optical applications like anti-counterfeiting is crucial.

Purpose of the Study:

• To fabricate carbon dot fibers with enhanced fluorescence stability for random laser applications.
• To utilize these carbon dot fibers for multilevel anti-counterfeiting systems.
• To investigate the tunability of lasing spectra and thresholds for secure authentication.

Main Methods:

• A single-step partial thermal decomposition method was employed to synthesize carbon dot fibers.
• Random lasers were generated from different carbon dot fiber types using 370 nm excitation at room temperature.
• Lasing spectra and thresholds were tuned by controlling decomposition times and fiber diameters.

Main Results:

• Carbon dot fibers exhibited superior fluorescence stability under high temperature and humidity.
• Random lasers were successfully achieved with tunable lasing spectra (428–560 nm) and thresholds (2–25 mJ cm⁻²).
• The simultaneous tuning of spectral and threshold characteristics provides a unique signature for anti-counterfeiting.

Conclusions:

• The fabricated carbon dot fibers are suitable for creating stable random lasers.
• The tunable lasing properties enable a robust multilevel anti-counterfeiting strategy.
• This approach significantly enhances system security by making counterfeiting extremely difficult.