Continuous tuning of an electrically tunable external-cavity semiconductor laser

Area of Science:

• Optics and Photonics
• Semiconductor Lasers
• Acousto-Optics

Background:

• External-cavity semiconductor lasers are crucial for tunable light sources.
• Achieving rapid and phase-coherent broadband tuning remains a challenge.
• Existing methods often lack full electronic control or are limited in speed.

Purpose of the Study:

• To propose and demonstrate a novel approach for rapid, phase-coherent, continuous broadband tuning of single-mode external-cavity semiconductor lasers.
• To enable precise electronic control over laser tuning parameters.
• To lay the groundwork for future mode-hop-free laser systems.

Main Methods:

• Utilized two internal acousto-optic devices for laser control.
• Employed acousto-optic devices to electronically manage the angle of light incident on a diffraction grating.
• Implemented electronic control of the effective round-trip phase within the laser cavity.

Main Results:

• Demonstrated a novel approach for tuning external-cavity semiconductor lasers.
• Achieved rapid and phase-coherent continuous broadband tuning.
• The system's phase control is derived from a long delay line, with potential for future mode-hop-free operation.

Conclusions:

• The proposed method successfully enables rapid and phase-coherent broadband tuning.
• The implemented electronic control via acousto-optic devices is effective.
• The approach is amenable to fully electronic control, paving the way for advanced laser systems.