On the Intensity Distribution Function of Blazed Reflective Diffraction Gratings

TL;DR

This paper derives a scalar diffraction model for blazed reflective gratings, clarifies the key geometric parameters affecting efficiency, and compares it with a rigorous vector approach to improve understanding of diffraction behavior.

Contribution

It provides a corrected scalar diffraction expression for blazed gratings and highlights the geometric factors influencing diffraction efficiency, correcting previous literature.

Findings

Scalar theory matches vector results for key parameters

Corrects a common expression in the literature

Identifies geometric parameters critical for efficiency

Abstract

We derive from first principles the expression for the angular/wavelength distribution of the intensity diffracted by a blazed reflective grating, according to a scalar theory of diffraction. We considered the most common case of a groove profile with rectangular apex. Our derivation correctly identifies the geometric parameters of a blazed reflective grating that determine its diffraction efficiency, and fixes an incorrect but commonly adopted expression in the literature. We compare the predictions of this scalar theory with those resulting from a rigorous vector treatment of diffraction from one-dimensional blazed reflective gratings.