Study on transition from photonic-crystal laser to random laser

Area of Science:

• Photonics
• Laser Physics
• Computational Physics

Background:

• Photonic crystals offer unique light manipulation properties.
• Positional disorder can significantly alter photonic crystal behavior.
• Understanding disorder effects is crucial for designing advanced laser devices.

Purpose of the Study:

• To investigate the dependence of the lasing threshold on positional disorder in photonic crystals.
• To explore the transition from photonic-crystal laser to random laser behavior.
• To identify novel phenomena related to disorder in laser systems.

Main Methods:

• Utilized the finite element method (FEM) for numerical simulations.
• Modeled a 2D photonic crystal with dielectric cylinders on a triangular lattice.
• Introduced positional disorder and an optically active medium.

Main Results:

• Systematically computed the lasing threshold for various degrees of positional disorder.
• Revealed the variation of the lasing threshold from photonic-crystal laser to random laser regimes.
• Discovered a novel phenomenon: a minimum lasing threshold at a specific disorder level.

Conclusions:

• The finite element method provides reliable accuracy for studying disorder in photonic crystals.
• Positional disorder influences the lasing threshold, leading to a transition in laser behavior.
• A minimum lasing threshold exists, suggesting optimal disorder levels for laser performance.