Classification of single-mode laser emission based on interferograms measured using a Fizeau wavemeter

Area of Science:

• Optical physics
• Laser technology
• Metrology

Background:

• High Q-factor etalons in optical interferometry demand single longitudinal mode (SLM) light sources for optimal detection sensitivity.
• Characterizing laser output typically involves external instruments like spectrometers or optical spectrum analyzers.

Purpose of the Study:

• To develop and validate a novel method for classifying laser output as single-mode or multi-mode using a commercial wavemeter.
• To assess the efficacy of heuristic metrics applied to wavemeter-generated interferograms for mode classification.

Main Methods:

• Interferograms from a commercial Fizeau interferometer-based wavemeter were analyzed using heuristic metrics.
• The method was validated on external cavity diode lasers (ECDLs) in the visible and near-infrared spectra.
• Results were cross-referenced with measurements from optical spectrum analyzers, spectrometers, and a scanning Fabry-Perot interferometer.

Main Results:

• The wavemeter-based heuristic metric approach successfully classified laser emissions as single-mode or multi-mode with high specificity.
• Validation confirmed the method's reliability across different laser types and wavelengths.
• The technique was successfully applied to an interferometric ultrasound sensor for acoustic transient measurement.

Conclusions:

• A commercial wavemeter, when analyzed with heuristic metrics, provides a viable and specific method for classifying laser emission modes.
• This approach offers advantages in applications requiring high spectral resolution, rapid data acquisition, and reliable single-mode classification.
• The method demonstrates practical utility in fields like optical sensing and metrology.