The invention provides a photo-
initiation system and application thereof. The photo-
initiation system comprises a
photosensitizer and a co-initiator, wherein the
photosensitizer is obtained by modifying a basic dye by using a modifier; the modifying agent is prepared from a C6-C20
alkyl sodium sulfosuccinate compound; the basic dye comprises at least one of ethyl violet, navy T, basic violet 7,
basic fuchsin,
methylene blue, neomethylene blue and azure A. The
photosensitizer in the photo-
initiation system provided by the invention is obtained by modifying the basic dye by using the modifier, and the types of the modifier and the basic dye are limited, so that when the photo-initiation system is used for preparing the
holographic grating, the photosensitizer is easily dispersed in a solution, is not easy to form a precipitate and is more easily bleached by visible light; therefore, the
diffraction efficiency, the
refractive index modulation degree and the
transmittance of the
holographic grating can be improved.