Synchronous characterization of semiconductor microcavity laser beam

Area of Science:

• Optics and Photonics
• Laser Physics
• Beam Characterization

Background:

• Understanding laser beam characteristics is crucial for applications.
• Previous methods lacked simultaneous intensity and frequency mapping.
• Laser frequency distribution and its relation to beam shape require detailed investigation.

Purpose of the Study:

• To develop and demonstrate a high-resolution double-channel imaging method.
• To synchronously map laser beam intensity and optical frequency distributions.
• To analyze the spatial and temporal characteristics of laser beams.

Main Methods:

• Utilizing a novel high-resolution double-channel imaging system.
• Synchronously capturing intensity and optical frequency data in the plane orthogonal to beam propagation.
• Performing temporal analysis at specific points within the beam cross-section.

Main Results:

• Demonstrated that laser frequency distribution is inhomogeneous below threshold and homogeneous above threshold within the fundamental Gaussian mode.
• Observed significant laser wavelength fluctuations in the beam tails, deviating from the Gaussian shape.
• Identified potential causes for wavelength fluctuations, including manufacturing imperfections and spontaneous emission in low-intensity wings.

Conclusions:

• The developed imaging method provides comprehensive spatial and temporal characterization of laser beams.
• The study elucidates the transition of laser frequency distribution from inhomogeneity to homogeneity with increasing power.
• Insights into beam defects and their spectral characteristics are gained, aiding in laser design and application.