Frequency doubling in periodic nonlinear photonic crystals mediated by random layers

Area of Science:

• Nonlinear optics
• Materials science
• Photonics

Background:

• Quadratic nonlinear photonic crystals are crucial for frequency conversion applications.
• Periodically poled structures offer precise control over light-matter interactions.
• Fabrication challenges exist for creating complex nonlinear structures.

Purpose of the Study:

• To develop a statistical theory for frequency doubling in nonlinear photonic crystals with randomly varied intermediate layers.
• To investigate the impact of random layer thickness variations on second-harmonic conversion efficiency.
• To predict novel phenomena in second-harmonic generation within these engineered structures.

Main Methods:

• Development of a statistical theory for frequency doubling.
• Numerical simulations to analyze the effect of random layer parameters.
• Analysis of second-harmonic conversion efficiency based on structural variations.

Main Results:

• The statistical theory accurately describes frequency doubling in structures with random layers.
• Conversion efficiency is sensitive to the number and thickness variations of intermediate layers.
• A new type of Maker-fringes-like oscillations in second-harmonic intensity was predicted.

Conclusions:

• Randomly layered nonlinear photonic crystals offer tunable control over frequency doubling.
• The developed theory provides a framework for designing optimized nonlinear optical devices.
• Potential for enhanced or suppressed second-harmonic generation through precise structural engineering.