High power Raman second stokes generation in a methane filled hollow core fiber.

Area of Science:

• Nonlinear Optics
• Fiber Lasers
• Gas Spectroscopy

Background:

• Developing efficient and high-power laser sources is crucial for various scientific and industrial applications.
• Raman fiber lasers offer a versatile platform for generating light at different wavelengths.
• Methane gas exhibits unique nonlinear optical properties exploitable for laser generation.

Purpose of the Study:

• To demonstrate a multi-watt, picosecond pulse duration laser source operating at 2.58 μm.
• To investigate the cascaded Raman process in methane-filled fibers.
• To model and understand the influence of gas pressure and fiber length on laser performance.

Main Methods:

• Utilizing a 1 μm disk laser source and a custom-designed Nested Anti-Resonant Nodeless fiber.
• Employing a cascaded Raman process to generate a second Stokes signal in methane gas.
• Experimentally varying gas pressure and propagation distance, and simulating results using the Generalized Nonlinear Schrodinger Equation.

Main Results:

• Achieved a maximum average power of 2.89 W (14.45 μJ) at 2.58 μm.
• Demonstrated the impact of gas pressure and propagation distance on the second Stokes signal power.
• Successfully modeled experimental outcomes, accounting for pressure-dependent gas-light interactions.

Conclusions:

• A robust multi-watt, picosecond laser source at 2.58 μm was successfully demonstrated.
• The study expands modeling capabilities for methane-filled fibers, including pressure gradients and infrared absorption effects.
• This work provides a valuable laser source and advances the understanding of nonlinear optics in gas-filled fibers.