Diffraction efficiency of a generalized complex binary grating

A generalized complex binary grating is a type of grating that permits control of four degrees of freedom: the two steps amplitudes that form the period, their relative phase and their widths' ratio. In this work, using the Fourier formalism, we derive an analytical expression for the diffracti...

Full description

Bibliographic Details
Authors: Amaya Robayo, Dafne Cecilia, Rueda, E., Vaveliuk, Pablo
Format: article
Status:Published version
Publication Date:2023
Country:Argentina
Institution:Consejo Nacional de Investigaciones Científicas y Técnicas
Repository:CONICET Digital (CONICET)
Language:Spanish
OAI Identifier:oai:ri.conicet.gov.ar:11336/227221
Online Access:http://hdl.handle.net/11336/227221
Access Level:Open access
Keyword:BINARY GRATINGS
DIFFRACTION EFFICIENCY
RONCHI GRATINGS
https://purl.org/becyt/ford/1.3
https://purl.org/becyt/ford/1
Description
Summary:A generalized complex binary grating is a type of grating that permits control of four degrees of freedom: the two steps amplitudes that form the period, their relative phase and their widths' ratio. In this work, using the Fourier formalism, we derive an analytical expression for the diffraction efficiency of all the grating diffraction orders. The analytical expression depends on the four degrees of freedom. Our model agrees with the results reported in the literature for the special cases of phase-only and amplitude-only Ronchi gratings and some particular extensions. In addition, we study situations where the amplitudes and widths of the grating steps differ. In particular, for a grating with a relative phase difference of π radians, normalized steps amplitudes of 1 and 0.77, and width’s ratios of 0.5 and 0.25, our experimental results validate the values predicted by our model. The model developed in this work will be valuable in designing high-precision diffractive gratings for particular specifications. In addition, it can be used to characterize spatial amplitude, phase and complex-amplitude modulators.