Fields of nonlinear cladding optical waveguides excited by butt-coupled linear waveguides at medium power levels

Area of Science:

• Nonlinear Optics
• Waveguide Optics
• Computational Physics

Background:

• Nonlinear optical waveguides are crucial for advanced photonic devices.
• Understanding light propagation in these structures is essential for device design.
• Previous studies have explored linear and high-power nonlinear regimes.

Purpose of the Study:

• To numerically investigate the behavior of medium power optical fields in nonlinear cladding waveguides.
• To analyze the winding path dynamics of light beams.
• To determine the influence of waveguide parameters and nonlinear effects on beam propagation.

Main Methods:

• Numerical simulation using mode matching of local normal modes.
• Modeling butt-coupled nonlinear cladding and linear waveguides.
• Analyzing beam path evolution under varying conditions.

Main Results:

• Medium power beams exhibit a winding path between the film and nonlinear cladding.
• Beams are non-stationary upon entering the nonlinear modal field and are forced to turn back.
• Lateral shift of the incident waveguide significantly alters the beam path.
• Saturation and linear absorption were found to dampen the oscillations of the winding path.

Conclusions:

• The study elucidates the complex propagation dynamics of medium power beams in nonlinear optical waveguides.
• Nonlinear cladding and waveguide geometry play critical roles in beam steering.
• Saturation and absorption offer potential mechanisms for controlling beam oscillation.