We report on highly transparent holographic phase transmission volume gratings recorded in the visible region at (Formula presented.) = 532 nm. The maximum measured diffraction efficiency is higher than 80% with a grating pitch of (Formula presented.) ≈ 300 nm and a refractive index modulation (Formula presented.) n ≈ 0.018. To obtain these results, we used a holographic mixture based on multi-reticulated acrylate and haloalkanes (1-bromo-butane and 1-bromo-hexane) and a synergic combination of camphore-quinone, which has a maximum absorbance at c.a. 470 nm, and R6G, here used as co-initiator, to efficiently initiate the photo-polymerization process. High transparent and high efficient holographic structures based on polymers can find applications in many research fields including integrated optics, sensors, high density data storage and security.
Top-Performance Transmission Gratings with Haloalkanes-Based Polymeric Composite Materials / Castagna, R.; Riminesi, C.; Di Donato, A.; Francescangeli, O.; Lucchetta, D. E.. - In: MATERIALS. - ISSN 1996-1944. - ELETTRONICO. - 15:23(2022), p. 8638. [10.3390/ma15238638]