Characterization of one-dimensional lasing in semiconductor disordered nanopowders

Area of Science:

• Condensed Matter Physics
• Photonics
• Materials Science

Background:

• Random lasers offer unique properties due to light scattering.
• Zinc Oxide (ZnO) is a promising material for nanolasers.
• Understanding the operational characteristics of ZnO random lasers is crucial for device development.

Purpose of the Study:

• To investigate the key parameters influencing the performance of one-dimensional ZnO-based random lasers.
• To characterize the relationship between pumping conditions, material properties, and laser output.
• To identify methods for achieving single-mode operation and optimizing laser intensity.

Main Methods:

• Utilized a time-domain traveling-wave model for simulation.
• Analyzed the effects of varying pump intensity and pump pulse width.
• Investigated the impact of nanopowder size and pump area on laser characteristics.
• Explored strategies for achieving single-mode lasing through nonuniform pumping.

Main Results:

• Increasing pump intensity initially increases, then saturates, the number of laser modes.
• Extended pump pulse width enhances laser mode appearance and output spectrum intensity.
• Nonuniform pumping enables single-mode laser operation.
• Optimal output intensity and sharpest laser modes observed for nanopowder sizes < 100 nm.
• Decreasing pump area leads to a lower lasing threshold.

Conclusions:

• Pump intensity, pulse width, nanopowder size, and pump area are critical factors in ZnO random laser performance.
• Nonuniform pumping is a viable technique for single-mode random laser generation.
• Nanopowder size below 100 nm is optimal for high-intensity, sharp-mode random lasing in ZnO.