Solid-core photonic bandgap fibers for cladding-pumped Raman amplification.

Area of Science:

• Optics and Photonics
• Laser Physics
• Materials Science

Background:

• Photonic bandgap fibers offer unique light-guiding properties.
• Raman fiber amplifiers are crucial for optical communications and high-power lasers.
• Power scaling of fiber amplifiers faces challenges like nonlinear effects and thermal management.

Purpose of the Study:

• To theoretically analyze cladding-pumped solid-core photonic bandgap Raman fiber amplifiers.
• To evaluate their potential for power scaling in high-power laser systems.
• To present a fiber design and simulation of a high-performance amplifier.

Main Methods:

• Theoretical analysis of cladding-pumped solid-core photonic bandgap fiber properties.
• Calculation of confinement loss at different wavelengths for a specific fiber design.
• Simulation of a Raman amplifier utilizing the proposed fiber, including output power and efficiency.

Main Results:

• A fiber design with a 46 µm mode field diameter and 250 µm cladding diameter was proposed.
• Calculated confinement losses were 0.12 dB/km (1st Stokes) and >10 dB/m (2nd Stokes) at 1.567 µm pump wavelength.
• Simulated amplifier achieved 85 kW output power, 78% optical conversion efficiency, and a heat load of 130 W/m over 235 m.

Conclusions:

• Cladding-pumped solid-core photonic bandgap Raman fiber amplifiers are promising for power scaling.
• The analyzed fiber design maintains low loss and large mode area under realistic conditions.
• The simulation results demonstrate high output power and efficiency, validating the amplifier concept.