Influence of ACPA on the stability of holographic transmission gratings stored in photopolymers

Abstract

RESUMEN:Este trabajo presenta los resultados obtenidos después de almacenar redes holográficas por transmisión con una frecuencia espacial de 954 líneas/mm y 2663 líneas/mm, en un material basado en PVA/AA. A la composición del material se le ha incorporado un agente acortador de cadenas, el 4,4´-azobis(4-cyanopentanoic acid) (ACPA) para mejorar la respuesta del material a la resolución espacial. Además, se ha aplicado un proceso de curado a las redes almacenadas para fijar el rendimiento en difracción y que no disminuya con el paso del tiempo.Palabras clave: Fotopolímeros, Redes Holográficas por Transmisión, Agente Acortador de Cadenas. ABSTRACT:This paper presents the results obtained after storing holographic transmission gratings with a spatial frequency of 954 lines/mm and 2663 lines/mm in a material based on PVA/AA. A chain transfer agent, the 4,4'-azobis (4-cyanopentanoic acid) (ACPA) has been incorporated in the material composition to improve the response to the spatial resolution. Furthermore, a curing process has been applied to the stored gratings in order to fix the diffraction efficiency over time.

Diffraction efficiency improvement in high spatial frequency holographic gratings stored in PVA/AA photopolymers: several ACPA concentrations

“…This composition provides diffraction efficiencies of 100% for holographic gratings with a spatial frequency of 1000 lines/mm. However, previous studies have shown that when you want to store holographic gratings with higher spatial frequencies, the diffraction efficiency decreases as the spatial frequency increases, and falls to a very small diffraction efficiency for spatial frequencies of 5000 lines/mm [22,28].…”

“…However, previous studies have shown that when you want to store holographic gratings with higher spatial frequencies, the diffraction efficiency decreases as the spatial frequency increases, and falls to a very small diffraction efficiency for spatial frequencies of 5000 lines/mm [22,29]. Fortunately, photopolymers are very versatile and it is possible to add new components to their composition.…”