Abstract: This paper introduces the course of photo-induced birefringence characteristic experiment of MO the azo dye-doped PVA thin film in modern physics experiments. The laboratory finding shows that the sample＇s ex- tent of reaction of photo-induced birefringence is in direct proportion to its exciting light power; in the case of certain exciting light power and 45° included angle between exciting light polarization direction and detecting light po- larization direction, sample＇s extent of reaction of photo-induced birefringence achieves maximum.

Key words: photo-induced birefringence, methyl orange dye-doped, PVA