Holographic Bragg gratings: measurements and examination diffraction parameters

TL;DR

This paper presents precise measurement techniques and analysis of diffraction parameters of thick holographic phase gratings recorded on PHC-488 photopolymer, validating theoretical models and exploring key optical characteristics for applications.

Contribution

It introduces a method for accurately determining grating parameters using Bragg angle measurements and validates the H. Kogelnik 2-wave coupled model with experimental data.

Findings

Validated theoretical model with experimental results

Achieved precise determination of grating parameters

Analyzed diffraction efficiency and spectral resolution

Abstract

Measurement and analysis of diffraction parameters of thick transmission holographic phase gratings recorded on PHC-488 photopolymer are presented. Precision determination of the spatial grating period is executed by Bragg angle measurement for two precisely known wavelengths in the first diffraction order and also by Bragg angle measurement on one wavelength in the first and second diffraction orders. Determination of actual grating thickness and depths of spatial modulation of a holographic recording, which are responsible for their main optical characteristics, is carried out with the application of H. Kogelnik 2-wave coupled model. Calculated and experimental Bragg angles in two orthogonal orientated planes of linear polarized laser light were used to confirm theoretical model with experimental results. Extreme values of the diffraction parameters, efficiency and spectral resolution, important for holographic phase grating applications are analyzed.