Carrier-envelope offset frequency linewidth narrowing in a Cr:forsterite laser-based frequency comb.

Area of Science:

• Laser Physics
• Spectroscopy
• Quantum Optics

Background:

• Cr:forsterite laser frequency combs are valuable for near-infrared spectroscopy.
• Self-referenced combs often have broad carrier-envelope offset frequency (f₀) linewidths, limiting spectral resolution.
• This broadening is linked to significant frequency noise across the comb's bandwidth.

Purpose of the Study:

• To stabilize a prism-based Cr:forsterite laser frequency comb.
• To investigate methods for narrowing the f₀ linewidth.
• To understand the noise dynamics responsible for f₀ narrowing.

Main Methods:

• Stabilization of a prism-based Cr:forsterite laser frequency comb.
• Systematic adjustment of prism insertion within the laser cavity.
• Introduction of a knife edge into the intracavity beam path.

Main Results:

• Narrowing of the f₀ linewidth from ~1.4 MHz to ~100 kHz solely by adjusting prism insertion.
• Further reduction of the f₀ linewidth to 23 kHz by introducing a knife edge.
• Investigation into the noise dynamics contributing to the observed linewidth reduction.

Conclusions:

• Prism insertion and knife edge modification are effective techniques for reducing f₀ linewidth in Cr:forsterite combs.
• These methods enhance spectral resolution for spectroscopic applications.
• Understanding noise dynamics is crucial for optimizing frequency comb performance.