Simple approach to the relation between laser frequency noise and laser line shape

Area of Science:

• Optics and Photonics
• Laser Physics
• Spectroscopy

Background:

• Laser frequency fluctuations are a primary cause of spectral line broadening.
• Existing methods for calculating laser linewidth are limited to power-law frequency noise spectra.
• A generalized approach is needed for arbitrary noise spectral densities.

Purpose of the Study:

• To develop a simplified method for evaluating laser linewidth.
• To provide an approximate formula applicable to non-power-law frequency noise spectra.
• To bridge the gap in understanding the relationship between arbitrary noise spectra and laser linewidth.

Main Methods:

• Derivation of a novel approximate formula for laser linewidth calculation.
• Analysis of the relationship between frequency noise spectral density and laser linewidth.
• Validation of the formula's applicability across diverse noise spectra.

Main Results:

• A simple, approximate formula for laser linewidth evaluation is presented.
• The formula successfully addresses frequency noise spectra deviating from power-law behavior.
• The approach offers a practical tool for characterizing laser line shapes.

Conclusions:

• The developed formula provides a versatile method for determining laser linewidth.
• This work simplifies the analysis of laser line broadening caused by complex frequency noise.
• The findings are crucial for applications requiring precise laser spectral characterization.