Coherent Random Lasing in Colloidal Quantum Dot-Doped Polymer-Dispersed Liquid Crystal with Low Threshold and High...

Area of Science:

• Materials Science
• Optics and Photonics
• Polymer Science

Background:

• Polymer-dispersed liquid crystals (PDLCs) offer unique optical properties.
• Quantum dots (QDs) provide efficient light emission for laser applications.
• Integrating QDs into PDLCs creates novel random laser materials.

Purpose of the Study:

• To prepare and characterize high-concentration ZnCdSeS/ZnS alloyed quantum dot-doped polymer-dispersed liquid crystals (QD-PDLCs).
• To investigate the effect of QD doping concentration on random laser performance.
• To evaluate the stability and potential applications of QD-PDLC random lasers.

Main Methods:

• Fabrication of QD-PDLCs using ultraviolet (UV) curing with varying concentrations (2-10 wt %).
• Morphological analysis of QD-PDLCs.
• Investigation of coherent random laser characteristics, including lasing threshold, line width, and stability.
• Assessment of pump position and area effects on laser performance.

Main Results:

• Optimized QD-PDLCs exhibited a low random laser threshold of 50 μJ/cm².
• Laser performance was sensitive to QD concentration and PDLC droplet characteristics.
• QD-PDLC lasers showed spatial localization effects due to random resonators.
• Excellent long-term stability was observed, with 92% emission intensity retained after 15 days.

Conclusions:

• High-concentration QD-PDLCs are effective gain media for random lasers.
• The developed QD-PDLCs demonstrate significant potential for applications in polymer random fiber lasers, sensors, and displays.
• The study highlights the tunability and stability of QD-PDLC random lasers.