Characteristics and instabilities of mode-locked quantum-dot diode lasers

Area of Science:

• Optics and Photonics
• Semiconductor Lasers

Background:

• Passively mode-locked quantum-dot diode lasers (QD MLLs) present significant characterization challenges.
• Limitations include low peak powers, high bandwidth, large time-bandwidth product, and substantial timing jitter.
• Existing pulse measurement techniques are inadequate for comprehensive analysis.

Purpose of the Study:

• To identify the shortcomings of current pulse measurement methods for QD MLLs.
• To introduce novel approaches for analyzing frequency-resolved optical gating (FROG) data.
• To enable full pulse characterization of QD MLLs.

Main Methods:

• Analysis of the origins of inadequacy in current pulse measurement techniques.
• Development of new methods for examining FROG data.
• Application of a partial coherence model for pulsed lasers.
• Utilizing a collinear configuration with an aperiodically poled lithium niobate waveguide-based FROG system.

Main Results:

• Established that simultaneous time-frequency characterization is necessary and sufficient for mode-locking characterization under the partial coherence model.
• Achieved full pulse characterization of QD MLLs.
• Demonstrated the effectiveness of the novel FROG data examination techniques.

Conclusions:

• The developed FROG analysis provides essential insights into the operation of QD MLLs.
• Simultaneous time-frequency characterization is key to understanding mode-locking in these lasers.
• The aperiodically poled lithium niobate waveguide-based FROG system offers a viable solution for QD MLL characterization.