Effect of Photovoltaic Induced Instabilities in Photorefractive Reflection Gratings in LiNbO$_{3}$:Fe

In LiNbO$_{3}$:Fe, photovoltaic induced instabilities are observed as sudden increases in transmitted power when recording photorefractive reflection gratings for contra-directional two-beam coupling applications. A beam diffracted off the grating while it forms will determine if the phase difference between the space-charge field and interference pattern temporarily changes or if the grating is briefly destroyed.