ALL-OPTICAL BYPASS-EXCHANGE SWITCH BASED ON 2 TYPES OF PHOTOREFRACTIVE HOLOGRAM

We demonstrate a scheme of using two types of recorded photorefractive hologram-a photovoltaic hologram and a standard photorefractive holog ram-to implement an all-optical bypass-exchange switch. A programmable polarization analyser array is used to select the desired operation. Issues about the elimination of noise are discussed with the help of p revious calculations by Yeh and Gu at al. As the system can be impleme nted in one single-block photorefractive crystal, it has the propertie s of compactness and miniaturization. Moreover, as the input and outpu t signals propagate in a direction normal to the switching array the s witch is extremely suitable for a multistage interconnected network.