A simple all-optical switch based on the photoinduced birefringence is demonstrated in azodye (DR1) doped polymer (PMMA) thin film. The all optical switching effect of the sample is studied at different control beam modulating frequency, different control beam power and different temperature of the sample. In this paper, with the control beam power of milliwatt magnitude, response time in several milliseconds and the depth of modulation above 60% of the all optical switch are obtained.