Mode-locking optimization with a real-time feedback system in a Nd:yttrium lithium fluoride laser cavity

Area of Science:

• Laser physics
• Optical engineering

Background:

• Mode-locked lasers are essential for generating ultrashort pulses.
• Maintaining pulse train stability is critical for consistent laser output.
• Existing methods for stability control can be complex or insufficient.

Purpose of the Study:

• To develop and implement an automatic control system for optimizing pulse train stability in a mode-locked laser cavity.
• To achieve real-time corrections for enhanced laser performance.

Main Methods:

• A closed-loop control system was designed.
• Cavity length was mechanically adjusted via a gear system acting on the rear cavity mirror.
• Envelope modulation of the mode-locked pulse train served as the controlled variable.

Main Results:

• The automatic control system successfully maintained the amplitude of the mode-locked pulse train stable within a few percent root mean square (rms).
• Real-time corrections were effectively implemented.
• The system demonstrated robust performance during the laser's working time.

Conclusions:

• The presented control system provides an effective solution for automatic optimization of pulse train stability in mode-locked lasers.
• This advancement is significant for applications requiring highly stable ultrashort laser pulses.
• The system's successful implementation on an Nd:yttrium lithium fluoride actively mode-locked laser validates its practical utility.