Closed-form Maker fringe formulas for poled polymer thin films in multilayer structures.

Area of Science:

• Nonlinear optics
• Materials science
• Thin film physics

Background:

• Maker fringe analysis is crucial for characterizing nonlinear optical materials.
• Accurate analysis requires accounting for wave reflections within multilayer structures.
• Existing models may not fully capture complex reflective behaviors in poled polymer films.

Purpose of the Study:

• To derive new closed-form expressions for Maker fringes in anisotropic and absorbing poled polymer thin films.
• To incorporate back reflections of fundamental and second-harmonic waves in multilayer structures.
• To provide a formulation for accurate characterization of nonlinear optical properties.

Main Methods:

• Derivation of expressions based on boundary conditions at each interface.
• Application to multilayer structures including buffer and transparent conducting oxide layers.
• Validation using experimental data and numerical simulations.

Main Results:

• New closed-form expressions for Maker fringes are reported.
• The formulation accounts for back reflections of fundamental and second-harmonic waves.
• Demonstrated the importance of including reflective layers for accurate characterization.

Conclusions:

• The new formulation enhances Maker fringe analysis for poled polymer thin films in multilayer systems.
• Accurate characterization of second-harmonic tensor elements requires considering reflective layers.
• This work provides a more reliable method for evaluating nonlinear optical properties of thin films.