A photorefractive oscillator was demonstrated in a c cut Ce doped plate and c cut Rh doped state BaTiO 3 crystals.The Model of Photorefractive quasi linear Fabry Perot cavity was set up using forward two wave mixing and contradirectional two wave mixing,and it was checked and analysed according to experimental results.And an analysis was made of the influence of the quasi linear Fabry Perot cavity on the stimulated photorefractive scattering self pumped phase conjugator (SPS SPPC).