Acoustically tuned erbium-doped fiber ring laser.

Area of Science:

• Photonics and Laser Technology
• Optical Engineering
• Fiber Optics

Background:

• Developing tunable lasers with narrow linewidths is crucial for applications like spectroscopy and optical communications.
• Existing tunable laser technologies often face limitations in tuning range, linewidth, or complexity.

Purpose of the Study:

• To report the first continuously tunable, narrow-linewidth laser utilizing an acousto-optic filter for a broad tuning range.
• To demonstrate a novel unidirectional ring-laser configuration with an erbium-doped fiber amplifier and an integrated acousto-optic filter.

Main Methods:

• Employed a unidirectional ring-laser configuration with an erbium-doped fiber amplifier as the gain medium.
• Integrated a frequency-shift-compensated acousto-optic filter as the key tuning element.
• Utilized a 980-nm optical pump with 60 mW of launched power.

Main Results:

• Achieved a 40 nm tuning range centered around 1545 nm.
• Demonstrated single-longitudinal-mode operation with a 10 kHz linewidth.
• Obtained nearly 2 mW of laser output power with 10% output coupling.

Conclusions:

• The developed acousto-optic tunable fiber laser represents a significant advancement in laser technology.
• The laser's broad tuning range and narrow linewidth are suitable for various demanding optical applications.
• Further investigation into mitigating wavelength hopping due to path-length fluctuations is warranted for enhanced stability.