Enhanced photorefractive gain in Cr-doped strontium barium niobate with an external dc electric field

Abstract
We present experimental results of field-enhanced photorefractive two-beam coupling and gain in Cr-doped strontium barium niobate crystals and its dependence on dopant concentrations. Increases in the exponential gain factor by more than a factor of 2 were observed by applying a field of up to 10 kV/cm. This property has potential applications such as switchable optical phase conjugators, limiters, and thresholding devices.