Far-detuned cascaded intermodal four-wave mixing in a multimode fiber

Area of Science:

• Nonlinear Optics
• Fiber Optics
• Laser Physics

Background:

• Parametric frequency conversion enables wavelength generation.
• Few-mode graded-index optical fibers support complex light interactions.
• Picosecond lasers provide high peak power for nonlinear processes.

Purpose of the Study:

• To demonstrate and analyze far-detuned parametric frequency conversion.
• To investigate the underlying mechanisms of sideband generation.
• To explore the spectral range achievable through this process.

Main Methods:

• Utilizing a Q-switched picosecond laser at 1064 nm as the pump source.
• Employing few-mode graded-index optical fibers.
• Conducting detailed analytical and numerical modeling.

Main Results:

• Successfully demonstrated far-detuned parametric frequency conversion.
• Identified complex cascaded processes involving inter-modal four-wave mixing.
• Achieved parametric wavelength detuning from visible (405 nm) to near-infrared (1355 nm).

Conclusions:

• Inter-modal four-wave mixing is key to generating multiple sidebands in this setup.
• Graded-index fibers facilitate broad spectral generation via parametric processes.
• This technique offers a pathway to efficient, wide-range wavelength generation.