Stable multi-wavelength fiber laser with single-mode fiber in a Sagnac loop

Area of Science:

• Photonics and Laser Technology
• Optical Engineering

Background:

• Multi-wavelength fiber lasers are crucial for high-capacity optical communication systems and advanced sensing.
• Mode competition is a significant challenge in achieving stable multi-wavelength laser operation.

Purpose of the Study:

• To propose and experimentally demonstrate a stable multi-wavelength fiber laser operating at 1.5 μm.
• To investigate the use of a Sagnac loop structure with intensity-dependent loss for mode competition suppression.

Main Methods:

• Utilized a Sagnac loop configuration incorporating a 48.6:51.4 coupler and 2 km of single-mode fiber (SMF).
• Leveraged the inherent intensity-dependent loss within the Sagnac loop to control laser cavity dynamics.
• Employed a 980 nm pump source with a maximum power of 300 mW.

Main Results:

• Achieved a stable multi-wavelength fiber laser output at 1.5 μm.
• Successfully obtained five distinct and stable lasing wavelengths.
• Demonstrated effective suppression of mode competition through the proposed Sagnac loop design.

Conclusions:

• The proposed Sagnac loop fiber laser design provides a stable multi-wavelength output.
• The intensity-dependent loss mechanism is effective in mitigating mode competition.
• This laser technology holds significant promise for future optical communication and sensing applications.