Use of forbidden singlet–triplet electron transitions in photopolymer material for holographic recording with high intensity nanosecond laser pulses

The goal of this research is recording of volume holograms in thick photopolymer material, based on the use of forbidden singlet–triplet transitions of the dye-sensitizer with high intensity (up to 12 GW cm−2) nanosecond pulses at λ=532nm. The material has threshold character of recording, that can lead to improved three-dimensional (3D) control of photochemical or photophysical processes. This is especially important for the microholographic approach to 3D multilayer optical data storage. The concentrations of the dye-sensitizer and electron donor in the photopolymer was optimized, and high value of refractive index change of 3.1⋅10−3 was achieved. The sensitivity of the material under research is much higher than the sensitivity of materials using two-photon absorption, which made it possible to record microholograms by a single laser pulse. Using the method of heterodyne detection, we also studied the spatial distribution of the optical inhomogeneity in photopolymer material. •Microholograms recording in thick samples of photopolymer material based on singlet–triplet transitions.•High value of refractive index change of 3.1 ⋅ 10-3 was achieved.•The recording has threshold character and the minimum value of the threshold was estimated as 1.33 GW/cm2 for recording by a single nanosecond pulse.