Voltage-tuned multiwavelength Raman ring laser with high tunability based on a single fiber Bragg grating

Area of Science:

• Photonics and Laser Technology
• Fiber Optic Sensing
• Materials Science

Background:

• Multiwavelength fiber lasers are crucial for applications like optical sensing and spectroscopy.
• Achieving stable, tunable, and high-performance multiwavelength fiber lasers remains a challenge.
• Fiber Bragg gratings (FBGs) offer a versatile platform for laser wavelength control.

Purpose of the Study:

• To develop a practical and tunable multiwavelength Raman fiber ring laser.
• To investigate the use of a single FBG with phase-shifted regions for wavelength selection.
• To demonstrate precise wavelength tunability using a voltage-controllable coil heater.

Main Methods:

• Utilizing a single fiber Bragg grating with multiple phase-shifted regions to generate multiple reflection peaks.
• Implementing a Raman fiber ring laser cavity.
• Employing a voltage-controllable coil heater to tune the lasing wavelengths.

Main Results:

• Achieved a stable multiwavelength Raman fiber ring laser with output peak-power fluctuation below 0.5 dB.
• Realized a high extinction ratio exceeding 50 dB.
• Demonstrated high flatness for three lasing peaks with a power difference less than 0.2 dB.
• Confirmed precise wavelength tunability of 0.11 nm/V for each lasing wavelength.

Conclusions:

• A practical and stable tunable multiwavelength Raman fiber ring laser was successfully demonstrated.
• The proposed scheme using a single FBG and a voltage-controlled heater offers effective wavelength control.
• The laser exhibits excellent performance characteristics, including stability, high extinction ratio, and flatness, making it suitable for advanced optical applications.