Critical dimension metrology and fitting models for polarization volume hologram grating based on liquid crystal polymer

The fabrication of high-performance diffractive waveguides is critically dependent on the precise control of grating physical dimensions, as even minor variations in thickness and slant angle can significantly affect optical performance. This study introduces a nondestructive spectroscopic ellipsometry technique designed to accurately characterize both the optical properties and physical dimensions of grating structures within liquid crystal polymer films. The proposed metrology method is rigorously validated against cross-sectional scanning electron microscopy, demonstrating its effectiveness in determining essential grating parameters.