Biophotopol’s energetic sensitivity improved in 300 μm layers by tuning the recording wavelength

•Volume transmission gratings obtained in 300 μm layers of Biophotopol.•A wavelength with a higher absorption improves the energetic sensitivity.•High diffraction efficiencies reached without significant attenuation.•A greater number of excited molecules lead to greater polymerization in a short time.

In order to obtain a highly environmentally compatible photopolymer to replace the well-known acrylamide photopolymer we optimized the previously developed Biophotopol composition to obtain volume transmission gratings in 300 μm layers, at a recording wavelength of 488 nm. The results obtained show an improved energetic sensitivity with similar diffraction efficiency to that obtained at the standard recording wavelength of 514 nm.