Investigations of Issues Relevant to the Application of Photon Echoes in Information Technology

Sammanfattning: Photon echoes have been studied both experimentally and theoretically, with the main part of the work centred around the concept of using photon echoes for all-optical data storage and processing. The four basic Boolean operators, AND, OR, NOT and XOR have been experimentally demonstrated using photon echoes. These constitute a complete set of Boolean operators. Selective erasure of digital data bits stored using photon echoes have been performed experimentally using three different laser systems with increasing frequency stabilities spanning three orders of magnitude, and the demands put on laser phase- and frequency stability using the suggested erasure method, have been studied. The effects of laser phase- and frequency fluctuations on both ordinary stimulated echoes and on coherently added echoes, have been analysed theoretically using the theory of stochastic processes. The resulting bit error rates in digital optical data processing systems due to such fluctuations have been considered. It has been shown possible experimentally to amplify photon echoes using fibre amplifiers, and to regenerate echoes from echoes amplified with this method. The advantages and limitations of this method for regeneration of photon echoes have been studied.