Self-pulsation in fiber-coupled, on-chip microcavity lasers

Area of Science:

• Photonics and Laser Technology
• Materials Science and Engineering
• Quantum Optics

Background:

• Erbium-doped fiber lasers are crucial for telecommunications.
• Microcavity lasers offer miniaturization and enhanced light-matter interaction.
• Understanding dynamic behaviors like self-pulsation is key for laser stability and applications.

Purpose of the Study:

• To investigate self-pulsation phenomena in an erbium-doped silica toroidal microcavity laser.
• To analyze the influence of pump power and taper-cavity coupling on pulse train dynamics.
• To interpret experimental findings using the ion-pair induced self-quenching model.

Main Methods:

• Fabrication of an erbium-doped silica toroidal microcavity.
• Coupling the microcavity to a tapered optical fiber.
• Optical pumping at 1444.8 nm and spectral analysis of lasing at 1560.2 nm.
• Systematic variation of pump power and coupling conditions.

Main Results:

• Demonstration of stable self-pulsation in the microcavity laser.
• Observation of distinct pulse train behaviors influenced by pump power.
• Correlation between taper-cavity coupling strength and pulsation characteristics.
• Threshold power for lasing determined to be 12 microwatts.

Conclusions:

• Self-pulsation is a viable dynamic regime for this microcavity laser system.
• Pump power and coupling conditions are critical parameters for controlling pulse dynamics.
• The ion-pair induced self-quenching model provides a valid framework for explaining the observed phenomena.