Power spectrum of a bistable external-cavity diode laser

Area of Science:

• Physics
• Optics
• Semiconductor Lasers

Background:

• Single-mode lasers with weak optical feedback can exhibit multistability.
• Frequency hopping in these systems significantly alters the output power spectrum.
• Understanding these spectral modifications is crucial for laser applications.

Purpose of the Study:

• To develop a novel spectral theory for frequency jumps in a two-mode external-cavity semiconductor laser.
• To derive an explicit analytical expression for the power spectrum of such a system.
• To quantify the spectral broadening caused by the hopping process.

Main Methods:

• Application of a novel spectral theory focused on frequency jumps.
• Analysis of a two-mode external-cavity semiconductor laser system.
• Derivation of an explicit analytical expression for the power spectrum.

Main Results:

• The derived power spectrum comprises four distinct contributions.
• Two contributions represent weighted sums of individual quasi-mode spectra.
• Two contributions quantify the additional spectral broadening due to frequency hopping.

Conclusions:

• The study provides a comprehensive analytical framework for understanding the power spectrum of semiconductor lasers with frequency hopping.
• The findings offer insights into spectral broadening mechanisms in multistable laser systems.
• This work contributes to the theoretical understanding of laser dynamics under optical feedback.