Multiwavelength Raman fiber laser with a continuously-tunable spacing

Area of Science:

• * Photonics and Laser Technology
• * Fiber Optics and Nonlinear Optics

Background:

• * Fiber lasers are crucial for various applications, but tunable multiwavelength operation remains a challenge.
• * Existing multiwavelength fiber lasers often lack independent control over channel number and spacing.

Purpose of the Study:

• * To propose and demonstrate a novel spacing-tunable multiwavelength Raman fiber laser.
• * To achieve independent adjustment of channel number and spectral spacing.

Main Methods:

• * Design of a free-spectral-range (FSR)-tunable comb filter using a superimposed chirped-fiber Bragg grating (CFBG).
• * Construction of a linear cavity incorporating a bandwidth-tunable CFBG reflector, a highly-nonlinear fiber for Raman gain, and an optical circulator-based loop mirror.

Main Results:

• * Achieved multiwavelength laser operation with tunable channel spacing from 0.3 to 0.6 nm.
• * Demonstrated independent adjustment of the number of lasing channels from 2 to 10.

Conclusions:

• * The proposed laser architecture provides flexible control over multiwavelength fiber laser parameters.
• * This advancement enables tailored laser outputs for diverse photonic applications.