Strongly enhanced mode selection in a thin dielectric-coated layered microcavity laser

Area of Science:

• Optics and Photonics
• Materials Science
• Laser Physics

Background:

• Microcavity lasers are crucial for various optical applications.
• Achieving strong mode selection is essential for laser stability and performance.
• Interferential coupling offers a pathway to enhance laser mode control.

Purpose of the Study:

• To investigate strong mode selection in a dielectric-coated layered cylindrical microcavity laser.
• To explore the role of enhanced interferential coupling in achieving mode selectivity.
• To optimize dielectric coating parameters for improved laser performance.

Main Methods:

• Fabrication of a thin dielectric-coated layered cylindrical microcavity using a fused silica capillary.
• Filling the capillary with a dye-doped liquid.
• Characterization of laser output and reflectivity at different coating thicknesses.
• Comparison with a bare capillary for mode selection efficacy.

Main Results:

• Observed strong mode selection attributed to an enhanced interferential coupling effect.
• Achieved enhanced reflectivity of approximately 50% at the dielectric-coated inner boundary.
• Identified an optimized coating thickness of around 0.4 micrometers.
• Demonstrated that lasing peaks occurred only at constructive interference wavelengths, unlike the weakly modulated output from a bare capillary.

Conclusions:

• Thin dielectric coatings can significantly enhance interferential coupling in cylindrical microcavity lasers.
• Optimized dielectric coatings enable strong mode selection, leading to highly specific lasing wavelengths.
• This approach offers a promising method for developing advanced laser sources with precise wavelength control.