Whispering-Gallery Mode Lasing in a Floating GaN Microdisk with a Vertical Slit.

Area of Science:

• Optics and Photonics
• Materials Science
• Nanotechnology

Background:

• Whispering-gallery mode (WGM) lasers are vital for optical applications.
• Controlling WGM laser properties like mode, direction, and quality factor is challenging.
• Existing methods lack simultaneous control over these critical parameters.

Purpose of the Study:

• To propose and demonstrate a novel microdisk design for simultaneous control of WGM laser properties.
• To achieve high-quality factor and low threshold in GaN floating microdisk lasers.
• To investigate the effect of a vertical slit on WGM lasing characteristics.

Main Methods:

• Fabrication of GaN microdisks with and without a vertical slit.
• Experimental measurement of whispering-gallery mode lasing spectra.
• Analysis of the influence of the slit on optical path and lasing resonance.

Main Results:

• Microdisks exhibit stable whispering-gallery mode lasing.
• The vertical slit modifies the optical path without disrupting lasing resonance.
• The slit influences the lasing mode, quality factor, and emission direction.

Conclusions:

• The proposed microdisk design with a vertical slit offers a feasible method for controlling WGM lasing properties.
• This approach is promising for developing advanced WGM lasers for various optical technologies.
• The study provides a pathway for tailoring laser performance through microcavity design.