Optical poling in germanium-doped microstructured optical fiber for visible supercontinuum generation

Area of Science:

• Nonlinear Optics
• Materials Science
• Photonics

Background:

• Supercontinuum generation is crucial for various photonic applications.
• Germanium-doped microstructured optical fibers offer unique nonlinear properties.
• Optical poling is a technique to induce specific nonlinear effects in materials.

Purpose of the Study:

• To report visible supercontinuum generation in germanium-doped microstructured optical fibers.
• To investigate the underlying nonlinear mechanisms.
• To demonstrate white-light emission generation.

Main Methods:

• Fabrication of germanium-doped microstructured optical fibers.
• Optical poling of the fabricated fibers.
• Pumping the fiber with a 1064 nm laser and its second harmonic (532 nm).
• Spectral analysis of the output emission.

Main Results:

• Visible supercontinuum generation was successfully achieved.
• The spectral broadening was initiated by second harmonic generation (SHG).
• Cross-phase modulation (XPM) between infrared (IR) solitons and the 532 nm wave was identified as the primary mechanism.
• Broadband white-light emission spanning 400-650 nm was observed on the fundamental propagation mode.

Conclusions:

• Optical poling enables efficient SHG in germanium-doped fibers for supercontinuum generation.
• XPM is a key process for achieving visible spectral broadening in this setup.
• The demonstrated technique offers a pathway for generating broadband visible light sources.