Two-wavelength holographic recording in photopolymer using four-energy-level system: Experiments and modeling

We investigate a two-wavelength method for recording a persistent hologram in a doped photopolymer. The recording method is based on two separated optical excitations of the four-energy-level system of the doped element, one at . 1/4 325 nm as the sensitizing wavelength and the other at . 1/4 647 nm as the writing wavelength, allowing for an experimental demonstration of nondestructive readout in phenanthrenequinonedoped poly(methyl methacrylate). Further, a four-energy-level rate equations model is proposed for describing the dynamics of hologram recording. The model successfully explains our experimental finding and further provides a general method to investigate such a two-wavelength holographic recording in photopolymer.