Low threshold gain metal coated laser nanoresonators.

Area of Science:

• Optics and Photonics
• Materials Science

Background:

• Metal-coated laser resonators often suffer from significant dissipation losses.
• Reducing these losses is crucial for developing more efficient and compact laser devices.

Purpose of the Study:

• To introduce and analyze a low refractive index layer to reduce losses in metal-coated laser resonators.
• To design a novel, ultra-compact laser resonator with improved performance.

Main Methods:

• Theoretical analysis of a gain medium waveguide with an inserted low refractive index layer.
• Optimization of the low index layer's thickness to minimize lasing threshold gain.
• Design and simulation of a three-dimensional cylindrical resonator based on waveguide analysis.

Main Results:

• The low refractive index layer significantly reduces dissipation losses in metal-coated laser resonators.
• An optimal thickness for the low index layer was identified, leading to a minimal lasing threshold gain.
• A novel cylindrical resonator, smaller than the vacuum wavelength in all dimensions, was designed.

Conclusions:

• The integration of a low refractive index layer is an effective strategy for loss reduction in laser resonators.
• The developed resonator design enables sub-wavelength lasing at room temperature, paving the way for miniaturized laser sources.