Holographic recording on photopolymers containing pyrene for enhanced fluorescence intensity

Photopolymer films containing pyrene were studied for fluorescence intensity enhancement by holographic recording. Photopolymer films were prepared from a solution containing a monomer mixture of s-triazine dimethacrylic monomer (DT) and ethylene glycol phenyl ether acrylate (PA), polysulfone as a binder, pyrene as a fluorescent dopant, and a visible light sensitive photoinitiator. The films were exposed by means of holographic techniques, resulting in a spatial intensity distribution in the films. The diffraction efficiency of the film containing 1 wt % of pyrene reached a maximum of 93%. The fluorescence intensity of the film was enhanced in conjunction with diffraction efficiency growth, proving that the increase in the fluorescence intensity of the film originated from the increased pyrene monomer emission in response to the increased viscosity around the pyrene molecules. The enhancement of the fluorescence intensity of the recorded area was ∼2 in reference to the unrecorded area. The recorded area showed grating, which could be identified by transmittance as well as fluorescence scan. The grating spacing and fluorescence intensity of the recorded area were correlated to the pyrene content and incident angle of recording beam.