Fundamental Noise Limits in Photorefractive Systems

When photorefractive materials are included as elements in image and signal processing systems, the dynamic range of the photorefractive element has a significant impact on the overall performance of the system. Evaluating the Emits on this dynamic range is of particular importance if we hope to provide a realistic comparison of photorefractive devices such as spatial light modulators1,2 or integrating correlators 3 with similar devices based on competing opto-electronic technologies. We must thus determine the range of signal beam intensities which may be used to write a holographic grating with a reference beam of some fixed intensity, or in other words, the maximum beam ratio that will cause a detectable refractive index grating to be written within the photorefractive material.