Self-sustained ultrafast pulsation in coupled vertical-cavity surface-emitting lasers

Area of Science:

• Optics and Photonics
• Semiconductor Lasers

Background:

• Vertical-cavity surface-emitting lasers (VCSELs) are crucial for optical communication.
• Generating high-frequency modulated laser light is essential for high-speed data transmission.

Purpose of the Study:

• To demonstrate high-frequency, narrow-band, self-pulsating intensity oscillation in coupled VCSELs.
• To investigate methods for enhancing this oscillation and controlling its frequency.

Main Methods:

• Utilizing two coupled vertical-cavity surface-emitting lasers (VCSELs).
• Analyzing the effect of collecting one of the two field lobes on oscillation intensity.
• Investigating the tunability of modulation frequency via inter-VCSEL separation and DC bias.

Main Results:

• Successfully generated high-frequency (over 40 GHz), narrow-band, self-pulsating intensity oscillation.
• Observed significant enhancement of oscillation by collecting a single field lobe.
• Demonstrated tunability of modulation frequency by adjusting inter-VCSEL separation and DC bias levels.
• Characterized the laser light as sinusoidally modulated with Gaussian-like near- and far-field profiles.

Conclusions:

• Coupled VCSELs offer an effective platform for generating high-repetition-rate, modulated laser light.
• Field lobe collection is a viable technique to enhance self-pulsating oscillations in VCSELs.
• The modulation frequency of coupled VCSELs can be precisely controlled for tailored applications.