Single-longitudinal-mode operation of a grating-based fiber-ring laser using self-injection feedback

Area of Science:

• Photonics and Optical Engineering
• Laser Physics
• Fiber Optic Sensing

Background:

• Single-longitudinal-mode (SLM) fiber lasers are crucial for applications requiring narrow spectral linewidth.
• Traditional methods for achieving SLM operation often involve complex cavity designs or active stabilization.
• Fiber Bragg gratings (FBGs) offer versatile solutions for wavelength selection and feedback in fiber optic systems.

Purpose of the Study:

• To propose and demonstrate a novel fiber-ring laser architecture for achieving stable SLM oscillation.
• To investigate the use of transmitted FBG light as a self-injection feedback mechanism.
• To characterize the performance of the proposed SLM fiber laser.

Main Methods:

• Construction of a fiber-ring laser incorporating a fiber Bragg grating (FBG).
• Utilizing the transmitted light of the FBG as self-injection feedback into the main ring cavity via an optical coupler.
• Detailed analysis of the SLM operation principle based on the self-injection feedback mechanism.

Main Results:

• Successful demonstration of a simple FBG-based fiber-ring laser.
• Achieved single-longitudinal-mode (SLM) oscillation through transmitted FBG light feedback.
• Reported output power of 6.6 dBm, optical signal-to-noise ratio (OSNR) of 57 dB at 1549.19 nm, and a short-term linewidth of 3.5 kHz.

Conclusions:

• The proposed FBG-based fiber-ring laser effectively utilizes transmitted light for self-injection feedback to ensure stable SLM oscillation.
• This simple and robust laser design offers high performance metrics suitable for various photonic applications.
• The demonstrated laser provides a cost-effective and efficient solution for generating narrow-linewidth optical signals.