Enhanced laser frequency stabilization to a high-finesse cavity through a combined feed-back and feed-forward...

Area of Science:

• Optics and Photonics
• Laser Physics
• Control Systems Engineering

Background:

• Laser frequency stabilization is crucial for precision measurements and applications.
• Existing methods like Pound-Drever-Hall locking can be complex and require specialized electronics.
• External modulators offer potential for noise reduction without altering the laser source itself.

Purpose of the Study:

• To demonstrate a novel and simple approach for laser frequency stabilization.
• To develop a method utilizing combined feedback and feed-forward control.
• To provide a versatile and efficient alternative to existing stabilization techniques.

Main Methods:

• Implementation of a combined feedback and feed-forward control scheme.
• Utilizing external modulators for the majority of noise reduction.
• Employing a stable high-finesse optical cavity as the frequency reference.
• Characterizing the stabilized output beam's power, tunability, and residual modulation.

Main Results:

• Achieved a tunable and stabilized laser output beam.
• Maintained optical power comparable to the original laser output.
• Demonstrated no residual frequency modulation in the stabilized output.
• Identified time delay in the frequency shifter as the primary performance limitation for the feed-forward loop.

Conclusions:

• The proposed combined feedback and feed-forward scheme offers a simple and effective method for laser frequency stabilization.
• The technique is versatile, applicable to various laser sources (near-infrared to near-UV).
• This solution presents a valid alternative to more complex electronic and optoelectronic systems, offering good power efficiency and optical purity.