Lasing of TM modes in a two-dimensional GaAs microlaser

Area of Science:

• Materials Science
• Optics and Photonics
• Semiconductor Physics

Background:

• Gallium arsenide (GaAs) single-quantum-well microlasers are typically fabricated with specific cavity designs.
• Previous studies on GaAs microlasers predominantly reported transverse electric (TE)-polarized emission.
• The Penrose unilluminable room is a complex two-dimensional cavity shape with unique optical properties.

Purpose of the Study:

• To fabricate and investigate the optical properties of an unstrained GaAs single-quantum-well microlaser with a Penrose room cavity.
• To characterize the lasing modes and polarization of the emission from this novel microlaser design.
• To understand the underlying physics responsible for any observed polarization phenomena.

Main Methods:

• Fabrication of an unstrained GaAs single-quantum-well microlaser.
• Utilizing a two-dimensional Penrose unilluminable room cavity design.
• Characterization of optical modes (axial, diamond-shaped, V-shaped) and emission polarization (TM-polarized).

Main Results:

• The Penrose room cavity supported quasi-one-dimensional modes, including axial, diamond-shaped, and V-shaped modes.
• Unexpectedly, the microlaser exhibited transverse magnetic (TM)-polarized emission, contrasting with previous TE-polarized observations in similar devices.
• The TM-polarized emission was attributed to the lasing of diamond-shaped modes near the Brewster angle at the cavity interface.

Conclusions:

• The Penrose unilluminable room cavity enables unique quasi-one-dimensional lasing modes in GaAs microlasers.
• The observed TM-polarized emission is a significant departure from typical GaAs microlaser behavior and is linked to specific mode dynamics.
• This study highlights the influence of cavity geometry on polarization properties and suggests potential for novel optical device applications.